[PATCH] wait_for_helper: trivial style cleanup

Use NULL instead of (... *)0
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/kmod.c

@@ -170,7 +170,7 @@ static int wait_for_helper(void *data)
 	sa.sa.sa_handler = SIG_IGN;
 	sa.sa.sa_flags = 0;
 	siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD));
-	do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0);
+	do_sigaction(SIGCHLD, &sa, NULL);
 	allow_signal(SIGCHLD);
 
 	pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);