11.0-BETA1 'ifconfig igb0 media auto' causes panic in llentry_free()

[Maxim Sobolev]

Hi, we are seeing consistent crash doing 'ifconfig igb0 media auto' after
interface has been provisioned by the dhcpclient. This is stable/11 sources
from svn revision 302593.

That problem did not happen to us before the upgrade from from 11.0-ALPHA3,
svn revision 301898 from head.

Sreenshot of the backtrace is here:
http://sobomax.sippysoft.com/DSC00012.JPG

-Maxim