[SCSI] use scmd_id(), scmd_channel() throughout code

Wrap a highly common idiom.  Makes the code easier to read, helps pave
the way for sdev->{id,channel} removal, and adds a token that can easily
by grepped-for in the future.

There are a couple sdev_id() and scmd_printk() updates thrown in as well.

Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/sym53c416.c b/drivers/scsi/sym53c416.c
index ef19adc..93dc7b6 100644
--- a/drivers/scsi/sym53c416.c
+++ b/drivers/scsi/sym53c416.c
@@ -773,7 +773,7 @@
 	current_command->SCp.Message = 0;
 
 	spin_lock_irqsave(&sym53c416_lock, flags);
-	outb(SCpnt->device->id, base + DEST_BUS_ID); /* Set scsi id target        */
+	outb(scmd_id(SCpnt), base + DEST_BUS_ID); /* Set scsi id target        */
 	outb(FLUSH_FIFO, base + COMMAND_REG);    /* Flush SCSI and PIO FIFO's */
 	/* Write SCSI command into the SCSI fifo */
 	for(i = 0; i < SCpnt->cmd_len; i++)