LU-14647 flr: mmap write/punch does not stale other mirrors

LU-14647 flr: mmap write/punch does not stale other mirrors

mmap write and punch/fallocate do not stale other mirrors and makes
FLR file contains different content in different mirrors.

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I93a3eb5ba898e3bf0ce108718506b742ed485da5
Reviewed-on: https://review.whamcloud.com/43470
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Wang Shilong <wshilong@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>