xwayland: Remove unneeded variable

Just a small code cleanup, there is no need to allocate a variable only
to check the return value of eglInitialize().

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
4 jobs for refactor-glamor-init in 4 minutes and 28 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Docker Image
passed debian-buster #6182578

00:00:10

 
  Build And Test
passed autotools #6182579

00:04:17

passed meson #6182580

00:01:42

passed meson-noglamor #6182581

00:00:48