qla2xxx: Fix for handling some error conditions in loopback.

qla2xxx: Fix for handling some error conditions in loopback.

Fixes the bug where in case we do not receive DCBX completion aen after a
set-port mbx Or when we get a bad status for IDC completion (mbx 8100) AEN
(i.e. bit 15 of mb2 is set) then we need to return error status and fail the
loopback operation.

JIRA Key: V2632FC-245

Acked-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Acked-by: Saurav Kashyap <saurav.kashyap@qlogic.com>