LU-5319 utils: update lr_reader to display additional data

LU-5319 utils: update lr_reader to display additional data

The lr_reader command currently displays only the server area
of the LAST_RCVD file of a Lustre ldiskfs target device.

This patch enhances the command to allow diplaying :
- the per-client area of the LAST_RCVD file
  when --client or -c option is specified
- the reply data of the REPLY_DATA file
  when --reply or -r option is specified
It still only support ldiskfs target device.

Signed-off-by: Gregoire Pichon <gregoire.pichon@bull.net>
Change-Id: Ifc2b7f9591eef0da5e4a5dc00f37e58484d4ea97
Reviewed-on: http://review.whamcloud.com/14862
Tested-by: Jenkins
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>