Hashmaps: Fix missing maintain calls in non-GLES.

Should only matter if vertex cache is enabled.

GPU/D3D11/DrawEngineD3D11.cpp

@@ -353,6 +353,7 @@ void DrawEngineD3D11::BeginFrame() {
 			vai_.Remove(hash);
 		}
 	});
+	vai_.Maintain();
 
 	// Enable if you want to see vertex decoders in the log output. Need a better way.
 #if 0

GPU/Directx9/DrawEngineDX9.cpp

@@ -338,6 +338,7 @@ void DrawEngineDX9::DecimateTrackedVertexArrays() {
 			vai_.Remove(hash);
 		}
 	});
+	vai_.Maintain();
 
 	// Enable if you want to see vertex decoders in the log output. Need a better way.
 #if 0

GPU/Vulkan/DrawEngineVulkan.cpp

@@ -354,6 +354,7 @@ void DrawEngineVulkan::BeginFrame() {
 			}
 		});
 	}
+	vai_.Maintain();
 }
 
 void DrawEngineVulkan::EndFrame() {