Remove chown'ing on adding dirs to osd-devices

When adding directories to osd-devices (e.g. juju config ceph-osd
osd-devices="/srv/ceph1 /srv/ceph2"), the charm was recursively changing
owner and group for all files below /var/lib/ceph, for each added
directory. This was taking time and was not useful.

The fix is to remove unnecessary recursive chown on /var/lib/ceph, since
ceph already manages the ownership of the files itself.

Change-Id: I39a00591bc86ec49c4ced53eadce75ddb21e2431
Closes-Bug: #1795383

lib/ceph/utils.py

@@ -1894,7 +1894,6 @@ def osdize_dir(path, encrypt=False, bluestore=False):
         return
 
     mkdir(path, owner=ceph_user(), group=ceph_user(), perms=0o755)
-    chownr('/var/lib/ceph', ceph_user(), ceph_user())
     cmd = [
         'sudo', '-u', ceph_user(),
         'ceph-disk',