Re: rc.d script style guide

[Greg Troxel <gdt%lexort.com@localhost>]

3) Checking for _arg

        # Backward compat with NetBSD <1.6:                                                                                                              [ -z "$rc_arg" ] && rc_arg=$_arg

Any reason not to gc this.   I think even the usual suspects are running
at least 1.6 by now :-)