LU-12546 mdt: abort recovery between MDTs

LU-12546 mdt: abort recovery between MDTs

Add an option to abort recovery between MDTs in case there is a
problem during recovery (e.g. MDT is missing or has broken logs),
but don't abort recovery between MDT and clients.

Change-Id: Id88f2b2ebae5cfa722dcac67c087b9b9a448721e
Signed-off-by: Hongchao Zhang <hongchao@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/36027
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>