watch-queue: remove spurious double semicolon

Sedat Dilek noticed that I had an extraneous semicolon at the end of a
line in the previous patch.

It's harmless, but unintentional, and while compilers just treat it as
an extra empty statement, for all I know some other tooling might warn
about it. So clean it up before other people notice too ;)

Fixes: 353f7988 ("watchqueue: make sure to serialize 'wqueue->defunct' properly")
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>

kernel/watch_queue.c

@@ -227,7 +227,7 @@ void __post_watch_notification(struct watch_list *wlist,
 
 		if (lock_wqueue(wqueue)) {
 			post_one_notification(wqueue, n);
-			unlock_wqueue(wqueue);;
+			unlock_wqueue(wqueue);
 		}
 	}