MFC 261518:

MFC 261518:
- Update a few places to account for va_copy().
- Create a separate 'return values' section and move some statements about
  return values to that section.
- Note that each invocation of va_start() and va_copy() must be paired with
  va_end() in the same function.

git-svn-id: svn://svn.freebsd.org/base/stable/10@262190 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f