ext2: add missing brelse() in ext2_new_inode()

There is a missing brelse of bitmap_bh in an error
path of ext2_new_inode().
Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/ext2/ialloc.c

@@ -509,6 +509,7 @@ struct inode *ext2_new_inode(struct inode *dir, umode_t mode,
 	/*
 	 * Scanned all blockgroups.
 	 */
+	brelse(bitmap_bh);
 	err = -ENOSPC;
 	goto fail;
 got: