LU-13827 utils: ofd_access_batch to print top hot files

LU-13827 utils: ofd_access_batch to print top hot files

with -F option one can specify fraction (in %%) of hot
files to be printed.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I131c47bb2252da88c9afce757c5264b8d2011d1a
Reviewed-on: https://review.whamcloud.com/39529
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Gu Zheng <gzheng@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>