LU-3536 lfsck: reuse parameter name for re-locating object

LU-3536 lfsck: reuse parameter name for re-locating object

Usually, LFSCK engine will locate the object against the bottom
device (OSD), then make related check/repair directly. Sometimes,
such as lfsck_namespace_repair_dirent(), we need to modify based
on LOD device. Under such case, the LFSCK will re-locate related
object with the same FID.

Originally, there is no special rules about the parameter's name,
that is confused which one should be used. For example, the input
parameter is named as "parent" that is against OSD, we need to
re-locate the obj based on the LOD, named as "pobj", then in the
subsequent logic, "pobj" should be used, but unfortunately, the
"parent" may be used by wrong. It is difficult to find out such
invalid usage.

To avoid such trouble, we prefer to reuse the (input) parameter
name after re-locating the object, name "pobj" as "parent".

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I5b6d7c5c10e1817ef2bade4931485228b26c511d
Reviewed-on: http://review.whamcloud.com/16932
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>