[yocto] Inadvertent RootFS permission pollution

[Bollinger, Seth]

Hello,

I recently ran into a problem where I had trouble determining why the setgid bit was set in my rootfs.  It turns out that debian has this bit set on /usr/local (where I was building from), and thus inherited this bit from that directory tree.  This surprised me, so I thought I would pass it along in case it saves anyone else some time.

Thanks,

Seth