egl/dri2: only destroy created objects

egl/dri2: only destroy created objects

dri2_display_destroy may be called by dri2_initialize_wayland_drm() if
initialization fails. In this case, these objects may not be initialized.

Cc: mesa-stable@lists.freedesktop.org
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
(cherry picked from commit 81d5c31631840db704337489cf677cc596da79f5)
[Andres Gomez: resolve trivial conflicts]
Signed-off-by: Andres Gomez <agomez@igalia.com>
Conflicts:
	src/egl/drivers/dri2/egl_dri2.c