This patch seperates the control of header split from LRO (which it

This patch seperates the control of header split from LRO (which it
was previously dependent on), LRO gets turned off when bridging but
its been found that header split is still a performance win in that case.

Secondly, there was some interface specific control in stats code that
has been missing, and a logic error that resulted in bogus reporting.
Thanks to Manish and John of LineRateSystems for the report and help in
this code.

Approved by: re

git-svn-id: svn://svn.freebsd.org/base/stable/8@196843 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f