cursor-renderer/native: Remove unnecessary endian check

Both cases have the same content.

GNOME/mutter!526
5 jobs for !526 with hardware-cursors in 14 minutes and 25 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Review
passed #612842
check-commit-log

00:00:25

 
  Build
passed #612843
build-mutter

00:10:47

passed #612844
build-without-native-backend-and-wayland

00:06:56

 
  Test
passed #612846
can-build-gnome-shell

00:01:45

passed #612845
test-mutter

00:03:12