LU-11623 llite: hash just created files if lock allows

LU-11623 llite: hash just created files if lock allows

If open|creat (and other intent operations later) returned a lookup
bit as part of the lock, hash the resultant dentry under this lock,
not to trigger further RPCs in subsequent lookups.

Lustre-change: https://review.whamcloud.com/33584
Lustre-commit: fc42cbe0e2e5d1d87d0edca73986b831ac718301

Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Signed-off-by: Oleg Drokin <green@whamcloud.com>
Change-Id: Id5140d1042af7f5ab9052922e11a7eda8f92a29a
Reviewed-on: https://review.whamcloud.com/38763
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>