Fix condition for calling set_pixmap_bo in drmmode_xf86crtc_resize
This matches CreateScreenResources_KMS. Fixes crash when resizing the screen (e.g. using xrandr) with depth < 24. Bugzilla: https://bugs.freedesktop.org/104914 Acked-by: Alex Deucher <alexander.deucher@amd.com>