Replace configASSERT( pcQueueName ) in vQueueAddToRegistry with a NULL pointer check. (#313)

* Replace configASSERT( pcQueueName ) in vQueueAddToRegistry with a NULL pointer check.

Fixes FreeRTOS/FreeRTOS-Kernel#311

* Make NULL checks consistent.

queue.c

@@ -2728,22 +2728,23 @@ BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue )
         UBaseType_t ux;
 
         configASSERT( xQueue );
-        configASSERT( pcQueueName );
 
         QueueRegistryItem_t * pxEntryToWrite = NULL;
 
+        if( pcQueueName != NULL )
+        {
             /* See if there is an empty space in the registry.  A NULL name denotes
              * a free slot. */
             for( ux = ( UBaseType_t ) 0U; ux < ( UBaseType_t ) configQUEUE_REGISTRY_SIZE; ux++ )
             {
                 /* Replace an existing entry if the queue is already in the registry. */
-            if( xQueueRegistry[ ux ].xHandle == xQueue )
+                if( xQueue == xQueueRegistry[ ux ].xHandle )
                 {
                     pxEntryToWrite = &( xQueueRegistry[ ux ] );
                     break;
                 }
                 /* Otherwise, store in the next empty location */
-            else if( ( NULL == pxEntryToWrite ) && ( xQueueRegistry[ ux ].pcQueueName == NULL ) )
+                else if( ( pxEntryToWrite == NULL ) && ( xQueueRegistry[ ux ].pcQueueName == NULL ) )
                 {
                     pxEntryToWrite = &( xQueueRegistry[ ux ] );
                 }
@@ -2752,8 +2753,9 @@ BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue )
                     mtCOVERAGE_TEST_MARKER();
                 }
             }
+        }
 
-        if( NULL != pxEntryToWrite )
+        if( pxEntryToWrite == NULL )
         {
             /* Store the information on this queue. */
             pxEntryToWrite->pcQueueName = pcQueueName;