contrib/dracut: export-zfs: simplify

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes openzfs#13093

contrib/dracut/90zfs/export-zfs.sh.in

@@ -3,28 +3,22 @@
 . /lib/dracut-zfs-lib.sh
 
 _do_zpool_export() {
-	ret=0
-	errs=""
-	final="${1}"
-
 	info "ZFS: Exporting ZFS storage pools..."
 	errs=$(export_all -F 2>&1)
 	ret=$?
-	[ -z "${errs}" ] || echo "${errs}" | vwarn
-	if [ "x${ret}" != "x0" ]; then
+	echo "${errs}" | vwarn
+	if [ "${ret}" -ne 0 ]; then
 		info "ZFS: There was a problem exporting pools."
 	fi
 
-	if [ "x${final}" != "x" ]; then
+	if [ -n "$1" ]; then
 		info "ZFS: pool list"
 		zpool list 2>&1 | vinfo
 	fi
 
-	return "${ret}"
+	return "$ret"
 }
 
 if command -v zpool >/dev/null; then
 	_do_zpool_export "${1}"
-else
-	:
 fi