MFC r253109, r253279:

MFC r253109, r253279:

r253109:
  Incorporate feedback from bde@ based on r252672 changes:

  * Use 0/1 instead of sysexits.  Man pages are confusing on this topic,
    but 0/1 is sufficient for nvmecontrol.
  * Use err function family where possible instead of fprintf/exit.
  * Fix some typing errors.
  * Clean up some error message inconsistencies.

r253279:
  %d should be used for printing int32_t instead of %zd.

  clang does not complain about this - only gcc.

Incorporated r253279 prior to MFC timeout because it is required for gcc
builds.

Approved by:	re (kib)

git-svn-id: svn://svn.freebsd.org/base/stable/9@253298 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f