sequencer: roll back lock file if write_message() failed

There is no need to wait until the atexit() handler kicks in at the end.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: dscho

sequencer.c

@@ -241,10 +241,14 @@ static int write_message(struct strbuf *msgbuf, const char *filename)
 	int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
 	if (msg_fd < 0)
 		return error_errno(_("Could not lock '%s'"), filename);
-	if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
-		return error_errno(_("Could not write to %s"), filename);
-	if (commit_lock_file(&msg_file) < 0)
+	if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0) {
+		rollback_lock_file(&msg_file);
+		return error_errno(_("Could not write to '%s'"), filename);
+	}
+	if (commit_lock_file(&msg_file) < 0) {
+		rollback_lock_file(&msg_file);
 		return error(_("Error wrapping up %s."), filename);
+	}
 
 	return 0;
 }