shm: don't get the display object before wl_resource_create

we don't need to get the display object for the client before
wl_resource_create success.
3 jobs for wayland_trivial_patch in 1 minute and 28 seconds (queued for 1 second)
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  Prep
passed #3372881
debian:buster@container-prep

00:00:18

 
  Build
passed #3372882
build-native-autotools

00:01:10

passed #3372883
build-native-meson

00:00:30