rtld(1): Fix a typo in inactive code.

Confirmed-by: kib@freebsd via marino
rc.d/root - Remove unnecessary 'mount /' call.

UFS and HAMMER do not emit an error when trying to mount
an already mounted root fileystem but cd9660 does.
That's why this wasn't producing any error message on
already installed systems.

While booting the LiveCD you could see:

cd9660: /dev/vcd0: Invalid argument

Reported-by: corecode
DragonFly-bug: <http://bugs.dragonflybsd.org/issues/1518>

This commit closes #1518