runtime: Fix prototype and one use of runtime_traceback.

From Richard Biener.

From-SVN: r205634

libgo/runtime/go-signal.c

@@ -218,7 +218,7 @@ runtime_sighandler (int sig, Siginfo *info,
 	  G *g;
 
 	  g = runtime_g ();
-	  runtime_traceback (g);
+	  runtime_traceback ();
 	  runtime_tracebackothers (g);
 
 	  /* The gc library calls runtime_dumpregs here, and provides

libgo/runtime/runtime.h

@@ -453,7 +453,7 @@ enum {
 };
 void	runtime_hashinit(void);
 
-void	runtime_traceback();
+void	runtime_traceback(void);
 void	runtime_tracebackothers(G*);
 
 /*