LU-10971 tests: use changelog routines in lustre-rsync-test

LU-10971 tests: use changelog routines in lustre-rsync-test

The lustre-rsync-test script has two subroutines to register
and deregister changelog users. These subroutines should be
updated to use changelog_register() and changelog_deregister()
found in test-framework.sh.

Test-Parameters: trivial clientcount=2 mdscount=2 mdtcount=4 osscount=1 ostcount=8 mdtfilesystemtype=zfs ostfilesystemtype=zfs testlist=lustre-rsync-test
Test-Parameters: clientcount=2 mdscount=2 mdtcount=4 osscount=1 ostcount=8 mdtfilesystemtype=ldiskfs ostfilesystemtype=ldiskfs testlist=lustre-rsync-test
Test-Parameters: clientcount=2 mdscount=1 mdtcount=1 osscount=1 ostcount=8 mdtfilesystemtype=ldiskfs ostfilesystemtype=ldiskfs testlist=lustre-rsync-test
Signed-off-by: James Nunez <james.a.nunez@intel.com>
Change-Id: Ia54095a6e039f6835def0f9c49157b71088d9e51
Reviewed-on: https://review.whamcloud.com/32208
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Wei Liu <wei3.liu@intel.com>
Reviewed-by: Saurabh Tandan <saurabh.tandan@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>