[SCSI] fcoe: stop delivery of received frames before doing lport_destroy()

To be more sure that no more input arrives at the local port as
it is being destroyed, clean the queues in the per-cpu receive
threads.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>