LU-7734 lnet: Update lnetctl usage

LU-7734 lnet: Update lnetctl usage

Bring lnetctl help descriptions, man page, and usage in line
with changes to peer functions.

Signed-off-by: Stephen Champion <schamp@sgi.com>
Test-Parameters: trivial
Change-Id: Idf115319727d92f23e50a97585f2f2c1e8c1b7b8
Reviewed-on: https://review.whamcloud.com/24279
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Olaf Weber <olaf@sgi.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Amir Shehata <amir.shehata@intel.com>