vmware_vga: Allow simple drivers to work without using the fifo

vmware_vga: Allow simple drivers to work without using the fifo

Postpone stopping the dirty log to the point where the command fifo is
configured to allow drivers which don't use the fifo to work too.
(Without this the picture rendered into the vram never got to the
screen and the DIRECT_VRAM option meant to support this case was
removed a year ago.)

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>