Exchanged two "${ZFS} get -H -o value" commands

Initramfs uses "get_fs_value()" elsewhere.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Signed-off-by: Garrett Fields <ghfields@gmail.com>
Closes #9736

contrib/initramfs/scripts/zfs.in

@@ -410,11 +410,11 @@ decrypt_fs()
 	if [ "$(zpool list -H -o feature@encryption $(echo "${fs}" | awk -F\/ '{print $1}'))" = 'active' ]; then
 
 		# Determine dataset that holds key for root dataset
-		ENCRYPTIONROOT=$(${ZFS} get -H -o value encryptionroot "${fs}")
+		ENCRYPTIONROOT="$(get_fs_value "${fs}" encryptionroot)"
 
 		# If root dataset is encrypted...
 		if ! [ "${ENCRYPTIONROOT}" = "-" ]; then
-			KEYSTATUS="$(${ZFS} get -H -o value keystatus "${ENCRYPTIONROOT}")"
+			KEYSTATUS="$(get_fs_value "${ENCRYPTIONROOT}" keystatus)"
 			# Continue only if the key needs to be loaded
 			[ "$KEYSTATUS" = "unavailable" ] || return 0
 			TRY_COUNT=3