i18n: fix unmatched single quote in error message

Fixed unmatched single quote introduced by commit:

 * f56fffef9a sequencer: teach write_message() to append an optional LF

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sequencer.c

@@ -248,7 +248,7 @@ static int write_message(const void *buf, size_t len, const char *filename,
 	}
 	if (append_eol && write(msg_fd, "\n", 1) < 0) {
 		rollback_lock_file(&msg_file);
-		return error_errno(_("could not write eol to '%s"), filename);
+		return error_errno(_("could not write eol to '%s'"), filename);
 	}
 	if (commit_lock_file(&msg_file) < 0) {
 		rollback_lock_file(&msg_file);