gl_rasterizer: Skip VB upload if the state is clean.

src/video_core/engines/maxwell_3d.h

@@ -1014,6 +1014,11 @@ public:
 
     struct DirtyFlags {
         bool vertex_attrib_format = true;
+        u32 vertex_array = 0xFFFFFFFF;
+
+        void OnMemoryWrite() {
+            vertex_array = 0xFFFFFFFF;
+        }
     };
 
     DirtyFlags dirty_flags;