jbd2: avoid memleak in jbd2_journal_write_metadata_buffer

The new_bh is from alloc_buffer_head, we should call free_buffer_head to
free it in error case.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240514112438.1269037-2-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/jbd2/journal.c

@@ -399,6 +399,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 		tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
 		if (!tmp) {
 			brelse(new_bh);
+			free_buffer_head(new_bh);
 			return -ENOMEM;
 		}
 		spin_lock(&jh_in->b_state_lock);