scsi: bnx2i: bnx2i_hwi: use swap macro in bnx2i_send_iscsi_nopout

Make use of the swap macro and remove unnecessary variable tmp.  This
makes the code easier to read and maintain.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Manish Rangankar <Manish.Rangankar@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>