LU-16988 mdd: update projid when merging layout

LU-16988 mdd: update projid when merging layout

When creating mirrors by the special directory ".lustre/fid",
the project ID could not be set correctly, which causes
wrong quota calculation for the projid.

Signed-off-by: Hongchao Zhang <hongchao@whamcloud.com>
Change-Id: Ia4c3a8973b8c467642e12629d36fa42d64162084
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51859
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sergey Cheremencev <scherementsev@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>