jbd commit: fix transaction dropping

We have to check that also the second checkpoint list is non-empty before
dropping the transaction.

Signed-off-by: Jan Kara <[e-mail]>
Cc: Chuck Ebbert <[e-mail]>
Cc: Kirill Korotaev <[e-mail]>
Cc: <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/jbd/commit.c

···
 	journal->j_committing_transaction = NULL;
 	spin_unlock(&journal->j_state_lock);
 
-	if (commit_transaction->t_checkpoint_list == NULL) {
+	if (commit_transaction->t_checkpoint_list == NULL &&
+	    commit_transaction->t_checkpoint_io_list == NULL) {
 		__journal_drop_transaction(journal, commit_transaction);
 	} else {
 		if (journal->j_checkpoint_transactions == NULL) {