staging: lustre: move struct netstrfns to nidstr.h

The reason struct netstrfns exist in nidstrings.c
was to avoid forward decleration errors. The best
way to handle this instead is to move this structure
to a header file. Since this structure is used in
the userland utilities as well so we place it in
nidstr.h which is exposed to userland.

Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6245
Reviewed-on: http://review.whamcloud.com/15083


Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>