xserver: Fix a typo

If `need_rotate` is TRUE, we should check for the right rotate.
3 jobs for fix-typo in 5 minutes and 55 seconds (queued for 1 second)
Status Job ID Name Coverage
  Docker Image
passed #759026
debian-testing

00:00:22

 
  Build And Test
passed #759027
autotools-build-and-test

00:05:32

passed #759028
meson-build-and-test

00:01:37