ir_to_mesa: don't init unfirom if link failed

Don't call set_unfiform_initializers if link failed, or it would trigger
a GL_INVALID_OPERATION error. That's not an expected behavior of
glLinkProgram function.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/mesa/program/ir_to_mesa.cpp

@@ -3458,7 +3458,9 @@ _mesa_glsl_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
       }
    }
 
-   set_uniform_initializers(ctx, prog);
+   if (prog->LinkStatus) {
+      set_uniform_initializers(ctx, prog);
+   }
 
    if (ctx->Shader.Flags & GLSL_DUMP) {
       if (!prog->LinkStatus) {