MFC r252269:

MFC r252269:

  Add an nvme_function structure array, defining the name, C function and
  usage message for each nvmecontrol command.  This helps reduce some code
  clutter both now and for future commits which will add logpage and
  firmware support to nvmecontrol(8).

  Also move helper function prototypes to the end of the header file, after
  the per-command functions.

Also add missing static keyword that glebius@ fixed as part of r252302.

Sponsored by: Intel

git-svn-id: svn://svn.freebsd.org/base/stable/9@252662 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f