Fix Xorg abort on exit in RHEL 7.7+

RHEL adds an extra LeaveVT calls to xf86CrtcCloseScreen when they build X server
for the purpose to drop drm master.

Signed-off-by: Slava Grigorev <slava.grigorev@amd.com>
12 jobs for master in 11 minutes and 42 seconds (queued for 11 seconds)
latest
Status Name Job ID Coverage
  Docker Image
passed debian-testing #593523

00:09:31

 
  Build
passed xserver-1.13 #593526

00:00:39

passed xserver-1.14 #593527

00:00:32

passed xserver-1.15 #593528

00:00:30

passed xserver-1.16 #593529

00:00:35

passed xserver-1.17 #593530

00:00:35

passed xserver-1.18 #593531

00:00:31

passed xserver-1.18-clang #593532

00:00:53

passed xserver-1.19 #593533

00:00:30

passed xserver-1.19-clang #593534

00:00:34

passed xserver-1.20 #593524

00:00:56

passed xserver-1.20-clang #593525

00:00:51