Fixed condition in InputDStream isTimeValid.

streaming/src/main/scala/spark/streaming/dstream/InputDStream.scala

@@ -29,7 +29,7 @@ abstract class InputDStream[T: ClassManifest] (@transient ssc_ : StreamingContex
       false // Time not valid
     } else {
       // Time is valid, but check it it is more than lastValidTime
-      if (lastValidTime == null || lastValidTime <= time) {
+      if (lastValidTime != null && time < lastValidTime) {
         logWarning("isTimeValid called with " + time + " where as last valid time is " + lastValidTime)
       }
       lastValidTime = time