staging: lustre: remove last entry of libcfs_netstrfns[]
Currently NID string handling test for the last entry,
and last entry has .nf_type == (__u32) -1. If we ask
for a non existent LND we hit the last entry which then
calls a strlen on a NULL which causes a error. We can
avoid this problem if we just remove the last entry
since it is not used for anything except as a last
entry marker.