Merge pull request #9910 from Tilka/postprocess

PostProcessing: fix shader compilation failures

Data/Sys/Shaders/lens_distortion.glsl

@@ -53,7 +53,7 @@ void main()
   float offsetAdd;
 
   // layer0 = left eye, layer1 = right eye
-  if (layer == 1)
+  if (src_layer == 1)
   {
     offsetAdd = stereoOffset;
   }

Source/Core/VideoCommon/PostProcessing.cpp

@@ -400,6 +400,8 @@ void PostProcessing::RecompileShader()
   m_pixel_shader.reset();
   if (!CompilePixelShader())
     return;
+  if (!CompileVertexShader())
+    return;
 
   CompilePipeline();
 }