egl: check for driver_configs in dri2_display_release

With later commits we'll split and reuse the destroy side of the
function for the initialize_foo error path.

In such cases, driver_configs may be NULL leading to a crash.

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
[Emil Velikov: reword commit message]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Tested-by: Rob Herring <robh@kernel.org>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 405db61..eefe3bf 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -919,7 +919,7 @@
     * the ones from the gbm device. As such the gbm itself is responsible
     * for the cleanup.
     */
-   if (disp->Platform != _EGL_PLATFORM_DRM) {
+   if (disp->Platform != _EGL_PLATFORM_DRM && dri2_dpy->driver_configs) {
       for (i = 0; dri2_dpy->driver_configs[i]; i++)
          free((__DRIconfig *) dri2_dpy->driver_configs[i]);
       free(dri2_dpy->driver_configs);