vrend: refactor vrender_get_glsl_version to return the value

There is no reason why this value should be obtained using a return
parameter. Also fix the version to return zero when the version string
doesn't follow the standard.

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Rohan Garg <rohan.garg@collabora.com>

src/vrend_renderer.c

@@ -757,7 +757,7 @@ static void vrend_destroy_query_object(void *obj_ptr);
 static void vrend_finish_context_switch(struct vrend_context *ctx);
 static void vrend_patch_blend_state(struct vrend_sub_context *sub_ctx);
 static void vrend_update_frontface_state(struct vrend_sub_context *ctx);
-static void vrender_get_glsl_version(int *glsl_version);
+static int vrender_get_glsl_version(void);
 static void vrend_destroy_program(struct vrend_linked_shader_program *ent);
 static void vrend_apply_sampler_state(struct vrend_sub_context *sub_ctx,
                                       struct vrend_resource *res,
@@ -6430,7 +6430,7 @@ struct vrend_context *vrend_create_context(int id, uint32_t nlen, const char *de
    vrend_renderer_create_sub_ctx(grctx, 0);
    vrend_renderer_set_sub_ctx(grctx, 0);
 
-   vrender_get_glsl_version(&grctx->shader_cfg.glsl_version);
+   grctx->shader_cfg.glsl_version = vrender_get_glsl_version();
 
    if (!grctx->ctx_id)
       grctx->fence_retire = vrend_clicbs->ctx0_fence_retire;
@@ -9883,12 +9883,11 @@ int vrend_create_so_target(struct vrend_context *ctx,
    return 0;
 }
 
-static void vrender_get_glsl_version(int *glsl_version)
+static int vrender_get_glsl_version(void)
 {
-   int major_local, minor_local;
+   int major_local = 0, minor_local = 0;
    const GLubyte *version_str;
    MAYBE_UNUSED int c;
-   int version;
 
    version_str = glGetString(GL_SHADING_LANGUAGE_VERSION);
    if (vrend_state.use_gles) {
@@ -9902,9 +9901,7 @@ static void vrender_get_glsl_version(int *glsl_version)
       assert(c == 2);
    }
 
-   version = (major_local * 100) + minor_local;
-   if (glsl_version)
-      *glsl_version = version;
+   return (major_local * 100) + minor_local;
 }
 
 static void vrend_fill_caps_glsl_version(int gl_ver, int gles_ver,