Use exit(4) when we don't want a panic coredump.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@2986 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_panic.c

@@ -297,7 +297,7 @@ pan_ic(const char *func, const char *file, int line, const char *cond, int err,
 	}
 #endif
 	if (params->diag_bitmap & 0x1000)
-		(void)kill(getpid(), SIGUSR1);
+		(void)exit(4);
 	else
 		abort();
 }