LU-14971 test: align mirror_io resync implementation

LU-14971 test: align mirror_io resync implementation

Align the mirror_io resync implementation with
llapi_mirror_resync_many().

Lustre-change: https://review.whamcloud.com/45202
Lustre-commit: 9898ae5347616a097193f69811a74af3ddd88349

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: Icf11c4c2302f36fc0f9682e0a310058081e1214f
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54327
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>