vmwlegacy: Fix a bug in screen dimension calculation
vmwlegacy: Fix a bug in screen dimension calculation

This bug resulted in incorrect screen dimensions and DPI being calculated
in some circumstances, leading to among other things bad aspect ratios in xine.

Signed-off-by: Thomas Hellstrom <a26490dfbee4be3d38287ad6448444504f58193c@vmware.com>

dezelin/xf86-video-vmware,dezelin/xf86-video-vmware,dezelin/xf86-video-vmware