When a rport goes offline, its speed setting was not reset. Subsequently, if
the rport was not deleted due to it coming back online within rport del
timeout, previously discovered speed would continue to show up. The fix is to
reset the speed when processing rport offline transition.

In rport attributes, rport's with unknown speed were indicated as TRL
enforced.  The right thing do to would be to use TRL default speed to
determine if TRL is enforced, when TRL is enabled.
Signed-off-by: NJing Huang <huangj@brocade.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>