Remove examples of gif_interfaces and gifconfig.  These have already been
marked as deprecated in rc.conf(5) manual page but these examples
were still here.

Spotted by:	jmg
Use correct length mask for split transactions. The hardware would
sometimes put non-zero values in the upper length bits, which are
available for high-speed-only USB transactions, breaking the reception
of data.
Move icl_pdu_get_data() and xpt_done() out of initiator's session lock.

During heavy reads data copying in icl_pdu_get_data() may consume large
percent of CPU time.  Moving it out of the lock significantly reduces
lock hold time and respectively lock congestion on read operations.

MFC after:	2 weeks
Fix use-after-free introduced in r274843.

I've missed that iscsi_outstanding_remove() frees the second pointer,
so it should no longer be used.  And in fact we don't really need to.

MFC after:	2 weeks
Merge remote-tracking branch 'freebsd/master' into hardened/current/master