Some graphics drivers keep CRTCs attached to disconnected outputs.
This could cause the XRandR 1.4 display device handler to incorrectly
mark outputs as mirrored. So enumerate outputs instead of CRTCs when
finding mirroring slaves.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=48932Signed-off-by: Zhiyi Zhang <zzhang@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>