[SCSI] qla2xxx: Implementation of bidirectional.

[jejb: merge fix for introduced warning]
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>