f2fs: return error of f2fs_lookup

Now we can report an error to f2fs_lookup given by f2fs_find_entry.

Suggested-by: He YunLei <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/dir.c

@@ -230,7 +230,7 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 
 	err = fscrypt_setup_filename(dir, child, 1, &fname);
 	if (err) {
-		*res_page = ERR_PTR(-ENOMEM);
+		*res_page = ERR_PTR(err);
 		return NULL;
 	}