metal: some fixes for MSAA

src/modules/graphics/metal/Texture.h

@@ -49,7 +49,7 @@ public:
 	ptrdiff_t getRenderTargetHandle() const override { return msaaTexture != nil ? (ptrdiff_t) msaaTexture : (ptrdiff_t) texture; }
 	ptrdiff_t getSamplerHandle() const override { return (ptrdiff_t) sampler; }
 
-	int getMSAA() const override { return 1 /* TODO*/; }
+	int getMSAA() const override { return actualMSAASamples; }
 
 	id<MTLSamplerState> getMTLSampler() const { return sampler; }
 
@@ -63,6 +63,8 @@ private:
 	id<MTLTexture> msaaTexture;
 	id<MTLSamplerState> sampler;
 
+	int actualMSAASamples;
+
 }; // Texture
 
 } // metal