[SCSI] bnx2fc: Replace scsi_dma_map() with dma_map_sg().

scsi_dma_map doesn't work for NPIV since vport dev isn't fully initialized.

For more details: http://marc.info/?l=linux-scsi&m=118312448030633&w=2

 and
commit - c59fd9eb.

Signed-off-by: Nithin Sujir <nsujir@broadcom.com>
Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>