[SCSI] qla4xxx: export iface name

Export the name of iface session is attached to. This is needed
so tools like iscsiadm/iscsistart can match the sessions to
userspace ifaces when rebuilding iscsid's state during boot.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>