cppcheck: (error) Uninitialized variable

As of cppcheck 1.82 warnings are issued when using the list_for_each_*
functions with an uninitialized variable.  Functionally, this is fine
but to resolve the warning initialize these variables.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes openzfs#9732

module/spl/spl-generic.c

@@ -649,7 +649,7 @@ static void __init
 spl_random_init(void)
 {
 	uint64_t s[2];
-	int i;
+	int i = 0;
 
 	get_random_bytes(s, sizeof (s));
 

module/spl/spl-kmem-cache.c

@@ -312,7 +312,7 @@ static spl_kmem_slab_t *
 spl_slab_alloc(spl_kmem_cache_t *skc, int flags)
 {
 	spl_kmem_slab_t *sks;
-	spl_kmem_obj_t *sko, *n;
+	spl_kmem_obj_t *sko;
 	void *base, *obj;
 	uint32_t obj_size, offslab_size = 0;
 	int i,  rc = 0;
@@ -356,6 +356,7 @@ spl_slab_alloc(spl_kmem_cache_t *skc, int flags)
 
 out:
 	if (rc) {
+		spl_kmem_obj_t *n = NULL;
 		if (skc->skc_flags & KMC_OFFSLAB)
 			list_for_each_entry_safe(sko,
 			    n, &sks->sks_free_list, sko_list) {
@@ -405,8 +406,8 @@ spl_slab_free(spl_kmem_slab_t *sks,
 static void
 spl_slab_reclaim(spl_kmem_cache_t *skc)
 {
-	spl_kmem_slab_t *sks, *m;
-	spl_kmem_obj_t *sko, *n;
+	spl_kmem_slab_t *sks = NULL, *m = NULL;
+	spl_kmem_obj_t *sko = NULL, *n = NULL;
 	LIST_HEAD(sks_list);
 	LIST_HEAD(sko_list);
 	uint32_t size = 0;
@@ -802,7 +803,7 @@ spl_magazine_free(spl_kmem_magazine_t *skm)
 static int
 spl_magazine_create(spl_kmem_cache_t *skc)
 {
-	int i;
+	int i = 0;
 
 	if (skc->skc_flags & KMC_NOMAGAZINE)
 		return (0);
@@ -833,7 +834,7 @@ static void
 spl_magazine_destroy(spl_kmem_cache_t *skc)
 {
 	spl_kmem_magazine_t *skm;
-	int i;
+	int i = 0;
 
 	if (skc->skc_flags & KMC_NOMAGAZINE)
 		return;
@@ -1617,7 +1618,7 @@ static spl_shrinker_t
 __spl_kmem_cache_generic_shrinker(struct shrinker *shrink,
     struct shrink_control *sc)
 {
-	spl_kmem_cache_t *skc;
+	spl_kmem_cache_t *skc = NULL;
 	int alloc = 0;
 
 	/*

module/spl/spl-kmem.c

@@ -303,7 +303,7 @@ kmem_del_init(spinlock_t *lock, struct hlist_head *table,
     int bits, const void *addr)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
+	struct hlist_node *node = NULL;
 	struct kmem_debug *p;
 	unsigned long flags;
 
@@ -500,7 +500,7 @@ static void
 spl_kmem_fini_tracking(struct list_head *list, spinlock_t *lock)
 {
 	unsigned long flags;
-	kmem_debug_t *kd;
+	kmem_debug_t *kd = NULL;
 	char str[17];
 
 	spin_lock_irqsave(lock, flags);

module/spl/spl-kstat.c

@@ -431,7 +431,7 @@ static struct seq_operations kstat_seq_ops = {
 static kstat_module_t *
 kstat_find_module(char *name)
 {
-	kstat_module_t *module;
+	kstat_module_t *module = NULL;
 
 	list_for_each_entry(module, &kstat_module_list, ksm_module_list) {
 		if (strncmp(name, module->ksm_name, KSTAT_STRLEN) == 0)
@@ -624,7 +624,7 @@ static int
 kstat_detect_collision(kstat_proc_entry_t *kpep)
 {
 	kstat_module_t *module;
-	kstat_proc_entry_t *tmp;
+	kstat_proc_entry_t *tmp = NULL;
 	char *parent;
 	char *cp;
 
@@ -659,7 +659,7 @@ kstat_proc_entry_install(kstat_proc_entry_t *kpep, mode_t mode,
     const struct file_operations *file_ops, void *data)
 {
 	kstat_module_t *module;
-	kstat_proc_entry_t *tmp;
+	kstat_proc_entry_t *tmp = NULL;
 
 	ASSERT(kpep);
 

module/spl/spl-proc.c

@@ -144,7 +144,7 @@ proc_doslab(struct ctl_table *table, int write,
 	int rc = 0;
 	unsigned long min = 0, max = ~0, val = 0, mask;
 	spl_ctl_table dummy = *table;
-	spl_kmem_cache_t *skc;
+	spl_kmem_cache_t *skc = NULL;
 
 	dummy.data = &val;
 	dummy.proc_handler = &proc_dointvec;
@@ -249,7 +249,7 @@ static int
 taskq_seq_show_impl(struct seq_file *f, void *p, boolean_t allflag)
 {
 	taskq_t *tq = p;
-	taskq_thread_t *tqt;
+	taskq_thread_t *tqt = NULL;
 	spl_wait_queue_entry_t *wq;
 	struct task_struct *tsk;
 	taskq_ent_t *tqe;

module/spl/spl-taskq.c

@@ -82,7 +82,7 @@ task_km_flags(uint_t flags)
 static int
 taskq_find_by_name(const char *name)
 {
-	struct list_head *tql;
+	struct list_head *tql = NULL;
 	taskq_t *tq;
 
 	list_for_each_prev(tql, &tq_list) {
@@ -211,7 +211,7 @@ task_expire_impl(taskq_ent_t *t)
 {
 	taskq_ent_t *w;
 	taskq_t *tq = t->tqent_taskq;
-	struct list_head *l;
+	struct list_head *l = NULL;
 	unsigned long flags;
 
 	spin_lock_irqsave_nested(&tq->tq_lock, flags, tq->tq_lock_class);
@@ -298,7 +298,7 @@ static void
 taskq_insert_in_order(taskq_t *tq, taskq_thread_t *tqt)
 {
 	taskq_thread_t *w;
-	struct list_head *l;
+	struct list_head *l = NULL;
 
 	ASSERT(tq);
 	ASSERT(tqt);
@@ -321,7 +321,7 @@ taskq_insert_in_order(taskq_t *tq, taskq_thread_t *tqt)
 static taskq_ent_t *
 taskq_find_list(taskq_t *tq, struct list_head *lh, taskqid_t id)
 {
-	struct list_head *l;
+	struct list_head *l = NULL;
 	taskq_ent_t *t;
 
 	list_for_each(l, lh) {
@@ -347,7 +347,7 @@ static taskq_ent_t *
 taskq_find(taskq_t *tq, taskqid_t id)
 {
 	taskq_thread_t *tqt;
-	struct list_head *l;
+	struct list_head *l = NULL;
 	taskq_ent_t *t;
 
 	t = taskq_find_list(tq, &tq->tq_delay_list, id);
@@ -1198,7 +1198,7 @@ param_set_taskq_kick(const char *val, struct kernel_param *kp)
 #endif
 {
 	int ret;
-	taskq_t *tq;
+	taskq_t *tq = NULL;
 	taskq_ent_t *t;
 	unsigned long flags;
 

module/spl/spl-tsd.c

@@ -98,7 +98,7 @@ static tsd_hash_table_t *tsd_hash_table = NULL;
 static tsd_hash_entry_t *
 tsd_hash_search(tsd_hash_table_t *table, uint_t key, pid_t pid)
 {
-	struct hlist_node *node;
+	struct hlist_node *node = NULL;
 	tsd_hash_entry_t *entry;
 	tsd_hash_bin_t *bin;
 	ulong_t hash;

module/spl/spl-vmem.c

@@ -50,7 +50,7 @@ EXPORT_SYMBOL(zio_arena);
 size_t
 vmem_size(vmem_t *vmp, int typemask)
 {
-	spl_kmem_cache_t *skc;
+	spl_kmem_cache_t *skc = NULL;
 	size_t alloc = VMEM_FLOOR_SIZE;
 
 	if ((typemask & VMEM_ALLOC) && (typemask & VMEM_FREE))