LU-14340 tests: remove stale test-framework functions

LU-14340 tests: remove stale test-framework functions

Delete functions not referenced anywhere in test-framework.sh
(each one will still appear only once, where it is defined):

  $ grep "^[a-z].* *()" lustre/tests/test-framework.sh |
  sed -e 's/function //' -e 's/ *(.*//' |
  while read F; do (( $(grep $F lustre/tests/*.sh | wc -l) > 1 )) ||
      echo "$F"
  done

  mdsdevlabel ostdevlabel cleanup_check obd_name unmount_zfs
  is_empty_fs get_svr_devs at_min_get canonical_path agts_nodes
  mixed_ost_devs setstripe_nfsserver delayed_recovery_enabled
  mds_on_old_device remove_ost_objects remove_mdt_files
  duplicate_mdt_files get_block_size

The unmount_zfs() function returned by the above check *is*
used via unmount_fstype() calling it as "unmount_$fstype".

Fixes: 5a3dfc2b5d90 ("LU-7301 tests: delete old lfsck tests")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I71842152a87f15918147da860745ef8e981f6121
Reviewed-on: https://review.whamcloud.com/41266
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Vikentsi Lapa <vlapa@whamcloud.com>
Reviewed-by: Elena Gryaznova <c17455@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>