remount-usr: mount doesn't report a change

It is arguable that this is a real change or not,
but in practice we have playbooks that report changes only for this and
it's very fun to scroll back each time to see if it's remount-usr or
a "real" change.

CHANGELOG.md

@@ -31,6 +31,7 @@ The **patch** part changes incrementally at each release.
 * redmine: use .my.cnf for mysql password
 * rbenv: change default Ruby version (2.5.1)
 * rbenv: switch from copy to lineinfile for default gems
+* remount-usr: mount doesn't report a change
 * squid: add a few news sites to the whitelist
 * tomcat: better nrpe check output
 * kvm-host: install kvm-tools package instead of copying add-vm.sh

remount-usr/tasks/main.yml

@@ -12,5 +12,6 @@
   command: 'mount -o remount,rw /usr'
   args:
     warn: no
+  changed_when: False
   when: usr_partition.rc == 0
   notify: remount usr