LU-12936 lnet: remove pt_number from lnet_peer_table.

LU-12936 lnet: remove pt_number from lnet_peer_table.

This fields is no longer used - except for an ASSERT().
It did have a use once, but that was removed in
Commit ffd8e881bb98 ("LU-2456 lnet: Dynamic LNet
                      Configuration (DLC)")

Test-Parameters: trivial
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I43d4c50d68fea3194f8515ac02599ef07b37ad60
Reviewed-on: https://review.whamcloud.com/36671
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Chris Horn <hornc@cray.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Amir Shehata <ashehata@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>