gl4: command_processor: fix locations in geometry shader header

The vertex shader outputs VertexData at location 1. Similarly, the pixel
shader's VertexData input is at location 1.

The geometry shader has both its input and output of VertexData at
location 0. Change it to location 1 so it matches the interface of
the other two shaders.

src/xenia/gpu/gl4/command_processor.cc

@@ -276,8 +276,8 @@ bool CommandProcessor::SetupGL() {
       "  vec4 o[16];\n"
       "};\n"
       "\n"
-      "layout(location = 0) in VertexData in_vtx[];\n"
-      "layout(location = 0) out VertexData out_vtx;\n";
+      "layout(location = 1) in VertexData in_vtx[];\n"
+      "layout(location = 1) out VertexData out_vtx;\n";
   // TODO(benvanik): fetch default point size from register and use that if
   //     the VS doesn't write oPointSize.
   // TODO(benvanik): clamp to min/max.