cnic: Fix missing ISCSI_KEVENT_IF_DOWN message

The iSCSI netlink message needs to be sent before the ulp_ops is cleared
as it is sent through a function pointer in the ulp_ops.  This bug
causes iscsid to not get the message when the bnx2i driver is unloaded.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>