MFC SVN r290340: Fix typo in error message

Submitted by: git_johnko.ca (John Ko)
Sponsored by: Smule, Inc.
Differential Revision: https://reviews.freebsd.org/D3997

MFC SVN revisions 272278,272379,275874:
r272278: Prevent buffer overflow(s) + style(9) nits
r272379: Optimize program performance + style(9) nits
r275874: Improve feedback to user by using dpv(3)

MFC SVN revisions 272278,272379,275874:
r272278: Prevent buffer overflow(s) + style(9) nits
r272379: Optimize program performance + style(9) nits
r275874: Improve feedback to user by using dpv(3)