LU-10248 mdd: set PFID for swap and merge layout

LU-10248 mdd: set PFID for swap and merge layout

It should update PFID for the OST objects if the layout has been
moved to another file. So far only swap and merge layout would
have this requirement.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: Ic2fd7d7a88cd0ef4501d2f02baf58dd177e07973
Reviewed-on: https://review.whamcloud.com/30292
Tested-by: Jenkins
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>