staging/lustre/lnet: peer aliveness status and NI status

staging/lustre/lnet: peer aliveness status and NI status

A couple of changes to improve aliveness detection:
- When LNet received a message, it can determine peer of this message
  is alive

- When LNet received a message from remote network, it can determine
  router is alive and NI status on router is UP.

Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-on: http://review.whamcloud.com/12453
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5485
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Isaac Huang <he.huang@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>