[SCSI] qla2xxx: Set the task attributes after memsetting fcp cmnd.

The memset of the fcp_cmnd struct needs to be moved so that it will not
zero-out valid data.

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>