service bus: Fix ServiceBusReceiveLinkProcessorTest unit test - addCredit api invocation count error (Azure#20073)

* Service bus Fix live test failure . closing processor

Author: hemanttanwar

sdk/servicebus/azure-messaging-servicebus/src/test/java/com/azure/messaging/servicebus/implementation/ServiceBusReceiveLinkProcessorTest.java

@@ -140,6 +140,9 @@ void createNewLink() {
         assertFalse(processor.hasError());
         assertNull(processor.getError());
 
+        // dispose the processor
+        processor.dispose();
+
         // Add credit for each time 'onNext' is called, plus once when publisher is subscribed.
         verify(link1, times(3)).addCredits(eq(PREFETCH - 1));
     }
@@ -571,6 +574,9 @@ void receivesFromFirstLink() {
         assertFalse(processor.hasError());
         assertNull(processor.getError());
 
+        // dispose the processor
+        processor.dispose();
+
         // Add credit for each time 'onNext' is called, plus once when publisher is subscribed.
         verify(link1, times(3)).addCredits(eq(PREFETCH));
         verify(link1).setEmptyCreditListener(creditSupplierCaptor.capture());  // Add 0.