video_core: gl_shader_manager: Only set shader samplers on fragment shader.

- Avoids unnecessary uniform errors.

src/video_core/renderer_opengl/gl_shader_manager.cpp

@@ -177,9 +177,12 @@ public:
             OGLProgram& program = boost::get<OGLProgram>(shader_or_program);
             program.Create(true, {shader.handle});
             SetShaderUniformBlockBindings(program.handle);
+
+            if (type == GL_FRAGMENT_SHADER) {
                 SetShaderSamplerBindings(program.handle);
             }
         }
+    }
 
     GLuint GetHandle() const {
         if (shader_or_program.which() == 0) {