call_usermodehelper: no need to unblock signals

____call_usermodehelper() correctly calls flush_signal_handlers() to set
SIG_DFL, but sigemptyset(->blocked) and recalc_sigpending() are not
needed.

This kthread was forked by workqueue thread, all signals must be unblocked
and ignored, no pending signal is possible.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/kmod.c

@@ -134,11 +134,8 @@ static int ____call_usermodehelper(void *data)
 	struct subprocess_info *sub_info = data;
 	int retval;
 
-	/* Unblock all signals */
 	spin_lock_irq(&current->sighand->siglock);
 	flush_signal_handlers(current, 1);
-	sigemptyset(&current->blocked);
-	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
 	/* We can run anywhere, unlike our parent keventd(). */