glsl: move shader cache lookup call to st

The nir shader cache read call is just below this call now so the code
is easier to follow.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31500>

src/compiler/glsl/linker.cpp

@@ -115,9 +115,4 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
          linker_error(prog, "no shaders attached to the program\n");
       return;
    }
-
-#ifdef ENABLE_SHADER_CACHE
-   if (shader_cache_read_program_metadata(ctx, prog))
-      return;
-#endif
 }

src/mesa/state_tracker/st_glsl_to_nir.cpp

@@ -985,9 +985,13 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
    prog->data->spirv = spirv;
 
    if (prog->data->LinkStatus) {
-      if (!spirv)
+      if (!spirv) {
          link_shaders(ctx, prog);
-      else
+
+#ifdef ENABLE_SHADER_CACHE
+         shader_cache_read_program_metadata(ctx, prog);
+#endif
+      } else
          _mesa_spirv_link_shaders(ctx, prog);
    }