LU-7734 lnet: Add peer_ni and NI stats for DLC

LU-7734 lnet: Add peer_ni and NI stats for DLC

This patch adds three stats to the peer_ni and NI structures:
send_count, recv_count, and drop_count. These stats get printed
when you do an "lnetctl net show -v" (for NI) and
"lnetctl peer show" (for peer_ni).

Signed-off-by: Doug Oucharek <doug.s.oucharek@intel.com>
Change-Id: Ic41c88cbc68dba677151d87a1fab53a48d36ea29
Reviewed-on: http://review.whamcloud.com/20170
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Amir Shehata <amir.shehata@intel.com>