MFC r299524

MFC r299524

  Use strlcpy() instead of strncpy() when copying the encoding value
  to ensure that the destination is NUL terminated.  Length truncation
  of one more character should not be an issue since encoding values
  that long are not supported by libc.  The destination string is
  treated as a NUL terminated string, but it is only passed to strcmp()
  for comparison to a set of shorter, fixed length strings, so this
  is not a serious problem.

Reported by:	Coverity
CID:		974769

git-svn-id: svn://svn.freebsd.org/base/stable/10@300265 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f