xrandr: Remove test against RANDR_MAJOR/RANDR_MINOR

xrandr: Remove test against RANDR_MAJOR/RANDR_MINOR

xrandr.c uses structures defined in <X11/extensions/Xrandr.h>
provided by 'libXrandr' package but tests structures availability
through RANDR_MAJOR/RANDR_MINOR defined in <X11/extensions/randr.h>
provided by 'randrproto' package.

Sometimes they are not in sync so it's safer to rely on checks made
by configure script through pkg-config.

In my test case, XRRPanning structure is not defined in Xrandr.h,
RANDR_MAJOR is 1 and RANDR_MINOR 2 but xrandr.c try to use it anyway.
(for the record, XRRPanning was added in libXrandr-1.2.91).

Signed-off-by: Yann Droneaud <ydroneaud@mandriva.com>
Reviewed-by: Rémi Cardona <remi@gentoo.org>