Fix random underflow.

Fixes: 63335997
Test: Boot a couple of Fugu's warm and cold and observe via top
      that mdns task is not hogging CPU cycles.

Change-Id: Ia03114fc282ee1484bb782bce614073e93e2490a
(cherry picked from commit 448cff811f242f271f2d473939f679c89f151758)
diff --git a/mDNSCore/mDNS.c b/mDNSCore/mDNS.c
index e126754..ddee3de 100755
--- a/mDNSCore/mDNS.c
+++ b/mDNSCore/mDNS.c
@@ -10641,7 +10641,7 @@
 	// Task Scheduling variables
 	result = mDNSPlatformTimeInit();
 	if (result != mStatus_NoError) return(result);
-	m->timenow_adjust = (mDNSs32)mDNSRandom(0xFFFFFFFF);
+	m->timenow_adjust = 0;            // b/63335997 , High outbound network traffic
 	timenow = mDNS_TimeNow_NoLock(m);
 
 	m->timenow                 = 0;		// MUST only be set within mDNS_Lock/mDNS_Unlock section