intel: Drop program size pointer from vec4/fs assembly getters.

These days, we're just passing a pointer to a prog_data field, which
we already have access to.  We can just use it directly.

(In the past, it was a pointer to a separate value.)

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>

src/intel/compiler/brw_fs.h

@@ -395,7 +395,7 @@ public:
 
    void enable_debug(const char *shader_name);
    int generate_code(const cfg_t *cfg, int dispatch_width);
-   const unsigned *get_assembly(unsigned int *assembly_size);
+   const unsigned *get_assembly();
 
 private:
    void fire_fb_write(fs_inst *inst,