[SCSI] bnx2fc: call ctlr_link_up only when the interface is enabled

Link may not be up when the driver receives ulp_start event, and hence
fcoe_ctlr_link_up is not called. Call fcoe_ctlr_link_up during
indicate_netevent only when the interface is enabled. (It has to be called when
enabled because that is an indication that the vlan discovery is completed).

Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>