JFS: 0 is not valid errno value so return NULL from jfs_lookup

Signed-off-by: Marcin Slusarz <[e-mail]>
Signed-off-by: Dave Kleikamp <[e-mail]>
Cc: [e-mail]
Cc: Alexander Viro <[e-mail]>

fs/jfs/namei.c

···
 		free_UCSname(&key);
 		if (rc == -ENOENT) {
 			d_add(dentry, NULL);
-			return ERR_PTR(0);
+			return NULL;
 		} else if (rc) {
 			jfs_err("jfs_lookup: dtSearch returned %d", rc);
 			return ERR_PTR(rc);