drm/qxl: make lots of things static.

/usr/lib/gcc/x86_64-linux-gnu/4.7/include/stddef.h:414:9: sparse: preprocessor token offsetof redefined
include/linux/stddef.h:17:9: this was the original definition
>> drivers/gpu/drm/qxl/qxl_drv.c:49:5: sparse: symbol 'qxl_modeset' was not declared. Should it be static?

Reported-by: kbuild test robot.
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/qxl/qxl_kms.c b/drivers/gpu/drm/qxl/qxl_kms.c
index 036e0de..85127ed 100644
--- a/drivers/gpu/drm/qxl/qxl_kms.c
+++ b/drivers/gpu/drm/qxl/qxl_kms.c
@@ -230,7 +230,7 @@
 	return 0;
 }
 
-void qxl_device_fini(struct qxl_device *qdev)
+static void qxl_device_fini(struct qxl_device *qdev)
 {
 	if (qdev->current_release_bo[0])
 		qxl_bo_unref(&qdev->current_release_bo[0]);