Cleanup.

src/renderer_mtl.mm

@@ -2333,12 +2333,11 @@ namespace bgfx { namespace mtl
 		ProgramMtl           m_screenshotBlitProgram;
 		RenderPipelineState  m_screenshotBlitRenderPipelineState;
 
-		CommandBuffer        m_commandBuffer;
-		CommandBuffer        m_prevCommandBuffer;
-		BlitCommandEncoder   m_blitCommandEncoder;
-		RenderCommandEncoder m_renderCommandEncoder;
+		CommandBuffer         m_commandBuffer;
+		BlitCommandEncoder    m_blitCommandEncoder;
+		RenderCommandEncoder  m_renderCommandEncoder;
 		ComputeCommandEncoder m_computeCommandEncoder;
-		FrameBufferHandle    m_renderCommandEncoderFrameBufferHandle;
+		FrameBufferHandle     m_renderCommandEncoderFrameBufferHandle;
 	};
 
 	RendererContextI* rendererCreate(const Init& _init)