drm/qxl: Remove qxl_debugfs_remove_files()

drm_debugfs_cleanup() now removes all minor->debugfs_list entries
automatically, so it's not necessary to call drm_debugfs_remove_files().

Cc: airlied@linux.ie
Cc: kraxel@redhat.com
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170307204924.1002-4-noralf@tronnes.org



[ kraxel: solved conflict ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>