Clang 13: Fix build errors ...

... due to local variables only being written to (but never read).

Signed-off-by: Daniel Edwards <dev@danieledwards.de>

Gems/EMotionFX/Code/EMotionFX/Source/Mesh.cpp

@@ -123,7 +123,7 @@ namespace EMotionFX
             TargetType* targetBuffer = static_cast<TargetType*>(targetVertexAttributeLayer->GetData());
 
             // Fill the vertex attribute layer by iterating through the Atom meshes and copying over the vertex data for each.
-            size_t addedElements = 0;
+            [[maybe_unused]] size_t addedElements = 0;
             for (const AZ::RPI::ModelLodAsset::Mesh& atomMesh : sourceModelLod->GetMeshes())
             {
                 const uint32_t atomMeshVertexCount = atomMesh.GetVertexCount();

Gems/EMotionFX/Code/EMotionFX/Source/Recorder.cpp

@@ -863,7 +863,7 @@ namespace EMotionFX
         }
 
         // process all objects for this frame
-        size_t totalBytesRead = 0;
+        [[maybe_unused]] size_t totalBytesRead = 0;
         const size_t numObjects = frameObjects.size();
         for (size_t a = 0; a < numObjects; ++a)
         {