Do not inherit $SYSRC_VERBOSE from operating environment. The concern is
that when a user (such as myself) which has SYSRC_VERBOSE=1 in his/her
~/.bash_profile or such that when they are told to execute a command like:
hostname `sysrc -n hostname`
NOTE: To activate a recently configured hostname.
If $SYSRC_VERBOSE is set, then POLA is violated because the output of sysrc
is indirectly influenced (making for an inconsistent experience).