new helper: signal_delivered()

Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
index 4ce6ab2..7362d58 100644
--- a/arch/um/kernel/signal.c
+++ b/arch/um/kernel/signal.c
@@ -61,7 +61,7 @@
 	if (err)
 		force_sigsegv(signr, current);
 	else
-		block_sigmask(ka, signr);
+		signal_delivered(signr, info, ka, regs, 0);
 }
 
 static int kern_do_signal(struct pt_regs *regs)