[lio-py]: Make --addnp do more complete port value appending and checking
[lio-py]: Make --addnp do more complete port value appending and checking

This patch makes lio_node.py --addnp in lio_target_add_np() do smarter
appending of the default port (3260) for IPv6 and IPv4 addreses if no
port value is provided by user.  This patch also makes sure that the passed
port is a valid non-zero u16 value, and will call lio_err() if not.

Signed-off-by: Nicholas A. Bellinger <978acd1567d5598152161fdf8bf3ca568f950c9b@linux-iscsi.org>

Datera/lio-utils,Datera/lio-utils,Datera/lio-utils,Datera/lio-utils