RenderBase: Ensure the draw size does not exceed the window size

This was happening when crop was enabled, causing blank outputs for some
Vulkan drivers (namely radv), as the draw rectangle is used as the
viewport.

Source/Core/VideoCommon/RenderBase.cpp

@@ -539,6 +539,10 @@ void Renderer::UpdateDrawRectangle()
     crop_width = win_width;
   }
 
+  // Clamp the draw width/height to the screen size, to ensure we don't render off-screen.
+  draw_width = std::min(draw_width, win_width);
+  draw_height = std::min(draw_height, win_height);
+
   // ensure divisibility by 4 to make it compatible with all the video encoders
   draw_width = std::ceil(draw_width) - static_cast<int>(std::ceil(draw_width)) % 4;
   draw_height = std::ceil(draw_height) - static_cast<int>(std::ceil(draw_height)) % 4;