staging: lustre: libcfs/nidstrings: Declare internal symbols static

This fixes sparse warnings:
  staging/lustre/lustre/libcfs/nidstrings.c:200:11: warning: symbol 'libcfs_nnetstrfns' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:203:1: warning: symbol 'libcfs_lo_str2addr' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:210:1: warning: symbol 'libcfs_ip_addr2str' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:227:1: warning: symbol 'libcfs_ip_str2addr' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:248:1: warning: symbol 'libcfs_decnum_addr2str' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:254:1: warning: symbol 'libcfs_hexnum_addr2str' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:260:1: warning: symbol 'libcfs_num_str2addr' was not declared. Should it be static?
  staging/lustre/lustre/libcfs/nidstrings.c:279:18: warning: symbol 'libcfs_lnd2netstrfns' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:292:18: warning: symbol 'libcfs_namenum2netstrfns' was not declared. Should it be static?
  drivers/staging/lustre/lustre/libcfs/nidstrings.c:307:18: warning: symbol 'libcfs_name2netstrfns' was not declared. Should it be static?

Some functions had static forward declarations followed by non-static
implementations. Those forward declarations are removed and the
implementations are declared static and moved into a location that
doesn't require forward declarations.

Signed-off-by: Sören Brinkmann <soeren.brinkmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>