If a -screen option specifies a screen number higher than any previously
specified, reallocate the vfb-private array of screen-info structs.
If built with a DIX that still has a MAXSCREENS limit, asking for too
many screens won't be detected until InitOutput calls AddScreen.
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Tiago Vignatti <tiago.vignatti@nokia.com>