Fix Coverity warnings: In most cases the return value of xTaskResumeAll() is cast to void when it is not needed. This PR fixes a couple of instances in the heap_n.c implementations where that was not the case.

portable/MemMang/heap_4.c

@@ -474,7 +474,7 @@ size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY use
 			} while( pxBlock != pxEnd );
 		}
 	}
-	xTaskResumeAll();
+	( void ) xTaskResumeAll();
 
 	pxHeapStats->xSizeOfLargestFreeBlockInBytes = xMaxSize;
 	pxHeapStats->xSizeOfSmallestFreeBlockInBytes = xMinSize;

portable/MemMang/heap_5.c

@@ -529,7 +529,7 @@ size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY use
 			} while( pxBlock != pxEnd );
 		}
 	}
-	xTaskResumeAll();
+	( void ) xTaskResumeAll();
 
 	pxHeapStats->xSizeOfLargestFreeBlockInBytes = xMaxSize;
 	pxHeapStats->xSizeOfSmallestFreeBlockInBytes = xMinSize;