LU-9859 lfsck: use Linux bitmap API

LU-9859 lfsck: use Linux bitmap API

Replace the use of the libcfs specific bitmap API used by lfsck
with the standard Linux bitmap API.

Change-Id: Icc0d9d2ceb9ca7b4b94dd728d9b9c499cf4d2414
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/47579
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>