[IA64] sys32_signal() forgets to initialize ->sa_mask

Pointed out by Oleg Nesterov <oleg@tv-sign.ru>, who in turn
got the hint from Linus.
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/ia32/ia32_signal.c

@@ -515,6 +515,7 @@ sys32_signal (int sig, unsigned int handler)
 
 	sigact_set_handler(&new_sa, handler, 0);
 	new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK;
+	sigemptyset(&new_sa.sa.sa_mask);
 
 	ret = do_sigaction(sig, &new_sa, &old_sa);