panfrost: Don't double-free when handling error for unsupported GPU

Setting the screen ro member before we checked gpu id means the error
case leads to a double-free because screen->ro is set and allocated
by parent who hanbdles de-alloc a second time after we destroyed the
screen we just created because ro was set.

Cc: mesa-stable

Signed-off-by: Carsten Haitzler <carsten.haitzler@foss.arm.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14516>

src/gallium/drivers/panfrost/pan_screen.c

@@ -854,8 +854,6 @@ panfrost_create_screen(int fd, struct renderonly *ro)
         if (dev->debug & PAN_DBG_NO_AFBC)
                 dev->has_afbc = false;
 
-        dev->ro = ro;
-
         /* Check if we're loading against a supported GPU model. */
 
         switch (dev->gpu_id) {
@@ -876,6 +874,8 @@ panfrost_create_screen(int fd, struct renderonly *ro)
                 return NULL;
         }
 
+        dev->ro = ro;
+
         screen->base.destroy = panfrost_destroy_screen;
 
         screen->base.get_name = panfrost_get_name;