staging: lustre: Avoid nid range related forward declarations in nidstring.c

Since forward declarations are frowned on upstream we move
the NID range handling to near the start of the nidstring.c
file.

Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: http://review.whamcloud.com/15086
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6245


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