runtime: fix bug introduced in revision 4a01b8d28570

R=rsc
CC=golang-dev
https://golang.org/cl/1874046

src/pkg/runtime/windows/thread.c

@@ -287,7 +287,7 @@ void
 call_syscall(void *args)
 {
 	StdcallParams *p = (StdcallParams*)args;
-	stdcall_raw(SetLastError, 1, 0);
+	stdcall_raw(SetLastError, 0);
 	p->r = (uintptr)stdcall_raw((void*)p->fn, p->args[0], p->args[1], p->args[2], p->args[3], p->args[4], p->args[5], p->args[6], p->args[7], p->args[8], p->args[9], p->args[10], p->args[11]);
 	p->err = (uintptr)stdcall_raw(GetLastError);
 	return;