ensure timekeeping_forward_now.constprop.8 and
timekeeping_forward_now.constprop.9 are correlated.

diff -Nupr src.orig/kernel/time/timekeeping.c src/kernel/time/timekeeping.c
--- src.orig/kernel/time/timekeeping.c	2016-12-15 19:56:00.136000000 +0000
+++ src/kernel/time/timekeeping.c	2016-12-15 19:56:30.496000000 +0000
@@ -1148,6 +1148,9 @@ void do_gettimeofday(struct timeval *tv)
 {
 	struct timespec64 now;
 
+	if (!tv)
+		return;
+
 	getnstimeofday64(&now);
 	tv->tv_sec = now.tv_sec;
 	tv->tv_usec = now.tv_nsec/1000;