staging: vboxvideo: make a couple of symbols static

Module parameter vbox_modeset and structure vbox_bo_driver do not need to
be in global scope and hence can be made static.

Cleans up a couple of sparse warnings:
symbol 'vbox_modeset' was not declared. Should it be static?
symbol 'vbox_bo_driver' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Michael Thayer <michael.thayer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vboxvideo/vbox_drv.c

@@ -36,7 +36,7 @@
 
 #include "vbox_drv.h"
 
-int vbox_modeset = -1;
+static int vbox_modeset = -1;
 
 MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
 module_param_named(modeset, vbox_modeset, int, 0400);

drivers/staging/vboxvideo/vbox_ttm.c

@@ -230,7 +230,7 @@ static void vbox_ttm_tt_unpopulate(struct ttm_tt *ttm)
 	ttm_pool_unpopulate(ttm);
 }
 
-struct ttm_bo_driver vbox_bo_driver = {
+static struct ttm_bo_driver vbox_bo_driver = {
 	.ttm_tt_create = vbox_ttm_tt_create,
 	.ttm_tt_populate = vbox_ttm_tt_populate,
 	.ttm_tt_unpopulate = vbox_ttm_tt_unpopulate,