Remove redundant variable.
In r114945 the line 'nmp = TAILQ_NEXT(mp, mnt_list);' was duplicated.
Instead of just removing the duplicate, convert the loop to TAILQ_FOREACH().
Make pdfork(2), pdkill(2) and pdgetpid(2) syscalls available for 32bit
binaries running under 64bit kernel.

Sponsored by:	The FreeBSD Foundation
Regenerate after r254447.

Sponsored by:	The FreeBSD Foundation