Fix sigreturn decoding on MIPS

From: Denys Vlasenko <dvlasenk@redhat.com>
Date: Thu, 9 Jun 2011 01:22:10 +0200

The "return 0" line was accidentally deleted circa 2007,
which made sigreturn on MIPS always display "= 0" return
instead of more informative " = ? (mask now [MASK])".

* strace.c (sys_sigreturn): Add wrongly deleted "return 0" line

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

Change-Id: Iddd9af8b8a75e02adb38c42faa4f6dec8060fb4f
diff --git a/signal.c b/signal.c
index ce5b462..5e73f8f 100644
--- a/signal.c
+++ b/signal.c
@@ -1500,6 +1500,7 @@
 		tcp->u_arg[0] = 0;
 		sp = regs.regs[29];
 		if (umove(tcp, sp, &si) < 0)
+			return 0;
 		tcp->u_arg[0] = 1;
 		tcp->u_arg[1] = si.si_mask;
 	} else {