copy_process(): remove the unneeded clear_tsk_thread_flag(TIF_SIGPENDING)

The forked child can have TIF_SIGPENDING if it was copied from parent's
ti->flags.  But this is harmless and actually almost never happens,
because copy_process() can't succeed if signal_pending() == T.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/fork.c

@@ -1029,7 +1029,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	p->vfork_done = NULL;
 	spin_lock_init(&p->alloc_lock);
 
-	clear_tsk_thread_flag(p, TIF_SIGPENDING);
 	init_sigpending(&p->pending);
 
 	p->utime = cputime_zero;