[SCSI] qla2xxx: Display proper link state for disconnected ports.

With qla2xxx using mid-layer async-scsi-scanning, the link state for
disconnected port is displayed wrong. Additional check for cable presence
is considered to display proper link state.

Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>