new helper: signal_setup_done()

usual "call force_sigsegv or signal_delivered" logics.  Takes
ksignal instead of separate siginfo/k_sigaction.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/signal.c b/kernel/signal.c
index 79998f5..775f555 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2396,6 +2396,15 @@
 	tracehook_signal_handler(sig, info, ka, regs, stepping);
 }
 
+void signal_setup_done(int failed, struct ksignal *ksig, int stepping)
+{
+	if (failed)
+		force_sigsegv(ksig->sig, current);
+	else
+		signal_delivered(ksig->sig, &ksig->info, &ksig->ka,
+			signal_pt_regs(), stepping);
+}
+
 /*
  * It could be that complete_signal() picked us to notify about the
  * group-wide signal. Other threads should be notified now to take