LU-15314 utils: set default max-inherit to 3

LU-15314 utils: set default max-inherit to 3

Change LMV_INHERIT_DEFAULT from 0 to 3. So that the default stripe
policy of dir will not be inherited unlimited and reduce performance
unexpectly.

Signed-off-by: Lei Feng <flei@whamcloud.com>
Test-Parameters: trivial
Change-Id: I67ef540046867ccec7ccc3aab035edbff95874c3
Reviewed-on: https://review.whamcloud.com/45874
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>
Reviewed-by: Oleg Drokin <green@whamcloud.com>