[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/ppa.c b/drivers/scsi/ppa.c
index fafcf5d..05347ee 100644
--- a/drivers/scsi/ppa.c
+++ b/drivers/scsi/ppa.c
@@ -740,7 +740,7 @@
 		}
 
 	case 2:		/* Phase 2 - We are now talking to the scsi bus */
-		if (!ppa_select(dev, cmd->device->id)) {
+		if (!ppa_select(dev, scmd_id(cmd))) {
 			ppa_fail(dev, DID_NO_CONNECT);
 			return 0;
 		}