hwc2: Skip hotplug uevent handling if client is not connected

Skip hotplug uevent handling if the client (SurfaceFlinger) is not
connected. The equivalent of hotplug uevent handling will be done once
when SurfaceFlinger connects, at RegisterCallback(), where the latest
connection states of all displays are read, so no uevent is lost.

CRs-Fixed: 2421144
Change-Id: I5ec9f90d9f44dc752a5edf8525868853ae4d7ad4
1 file changed