AthCUDA Warning Fixes, master branch (2020.07.07.)

While building AthExCUDA for an unrelated development recently, I had to realise that when CUDA is not available for the build, the code produces a lot of warnings. These changes are meant to fix all of those.

It's worth noting that this just highlights that we will need to turn on more rigorous warnings for the CUDA compilation in AtlasCompilerSettings.cmake...

Pinging @leggett and @fwinkl.

Control/AthCUDA/AthCUDACore/src/Memory.cu

@@ -76,11 +76,7 @@ namespace AthCUDA {
 
          // If a device is available, then free up the memory using CUDA.
          if( Info::instance().nDevices() != 0 ) {
-            taskArena().enqueue( ::DeviceDeleterTask( ptr )
-#if __TBB_TASK_PRIORITY
-                                 , tbb::priority_normal
-#endif // __TBB_TASK_PRIORITY
-                                );
+            taskArena().enqueue( ::DeviceDeleterTask( ptr ) );
             return;
          }
 
@@ -98,11 +94,7 @@ namespace AthCUDA {
 
          // If a device is available, then free up the memory using CUDA.
          if( Info::instance().nDevices() != 0 ) {
-            taskArena().enqueue( ::DeviceDeleterTask( ptr )
-#if __TBB_TASK_PRIORITY
-                                 , tbb::priority_normal
-#endif // __TBB_TASK_PRIORITY
-                                );
+            taskArena().enqueue( ::DeviceDeleterTask( ptr ) );
             return;
          }
 
@@ -120,11 +112,7 @@ namespace AthCUDA {
 
          // If a device is available, then free up the memory using CUDA.
          if( Info::instance().nDevices() != 0 ) {
-            taskArena().enqueue( ::HostDeleterTask( ptr )
-#if __TBB_TASK_PRIORITY
-                                , tbb::priority_normal
-#endif // __TBB_TASK_PRIORITY
-                                );
+            taskArena().enqueue( ::HostDeleterTask( ptr ) );
             return;
          }