egl/gbm: Remove check for EGLConfig presence

We now check in the EGL core that we actually have some configs for the
display, so no need to do it in the platform.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27709>

src/egl/drivers/dri2/platform_drm.c

@@ -492,7 +492,7 @@ swrast_get_image(__DRIdrawable *driDrawable, int x, int y, int width,
    gbm_dri_bo_unmap_dumb(bo);
 }
 
-static EGLBoolean
+static void
 drm_add_configs_for_visuals(_EGLDisplay *disp)
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
@@ -537,9 +537,9 @@ drm_add_configs_for_visuals(_EGLDisplay *disp)
             dri2_add_config(disp, dri2_dpy->driver_configs[i], config_count + 1,
                             EGL_WINDOW_BIT, attr_list, NULL, NULL);
          if (dri2_conf) {
+            format_count[j]++;
             if (dri2_conf->base.ConfigID == config_count + 1)
                config_count++;
-            format_count[j]++;
          }
       }
    }
@@ -551,8 +551,6 @@ drm_add_configs_for_visuals(_EGLDisplay *disp)
                  gbm_format_get_name(visuals[i].gbm_format, &desc));
       }
    }
-
-   return (config_count != 0);
 }
 
 static const struct dri2_egl_display_vtbl dri2_drm_display_vtbl = {
@@ -683,10 +681,7 @@ dri2_initialize_drm(_EGLDisplay *disp)
 
    dri2_setup_screen(disp);
 
-   if (!drm_add_configs_for_visuals(disp)) {
-      err = "DRI2: failed to add configs";
-      goto cleanup;
-   }
+   drm_add_configs_for_visuals(disp);
 
    disp->Extensions.KHR_image_pixmap = EGL_TRUE;
    if (dri2_dpy->image_driver)