Revert "drm/qxl: do not run release if qxl failed to init"

This reverts commit b91907a6.

Patch is broken, it effectively makes qxl_drm_release() a nop
because on normal driver shutdown qxl_drm_release() is called
*after* drm_dev_unregister().

Fixes: b91907a6

 ("drm/qxl: do not run release if qxl failed to init")
Cc: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20210204145712.1531203-3-kraxel@redhat.com