[SCSI] 3w-xxxx: remove unnecessary local_irq_save/restore for scsi sg copy API

Since the commit 50bed2e2 (sg: disable
interrupts inside sg_copy_buffer), no need to disable interrupts
before calling scsi_sg_copy_from_buffer. So we can simplify
tw_transfer_internal, which disables interrupts just for
scsi_sg_copy_from_buffer.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>\
Acked-by: NAdam Radford <linuxraid@amcc.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/3w-xxxx.c

@@ -1466,12 +1466,7 @@ static int tw_scsiop_inquiry(TW_Device_Extension *tw_dev, int request_id)
 static void tw_transfer_internal(TW_Device_Extension *tw_dev, int request_id,
 				 void *data, unsigned int len)
 {
-	struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-	unsigned long flags;
-
-	local_irq_save(flags);
-	scsi_sg_copy_from_buffer(cmd, data, len);
-	local_irq_restore(flags);
+	scsi_sg_copy_from_buffer(tw_dev->srb[request_id], data, len);
 }
 
 /* This function is called by the isr to complete an inquiry command */