nice,chroot: use more standard option parsing

nice,chroot: use more standard option parsing

Related to the 2010-03-25 commit, 88d4b346,
"timeout: use more standard option parsing".
* src/nice.c (main): Don't use parse_long_options()
which is a helper for commands that don't have any
long options specific to them.
* src/chroot.c (main): Likewise.
* tests/misc/nice-fail: Remove a case that now
passes due to us accepting multiple instances of the
--help and --version options.
* tests/misc/chroot-fail: Likewise.