staging: vboxvideo: Init fb_info.fix.smem once from fbdev_create

The fbdev compat fb gets pinned into VRAM at creation and then gets pinned
a second time when set as scanout buffer and unpinned when replaced, this
means its pin count never becomes less then 1, so it is always at the same
address and there is no need for the vbox_fbdev_set_base() call.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>