[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/imm.c b/drivers/scsi/imm.c
index 65e8456..fc0f30a 100644
--- a/drivers/scsi/imm.c
+++ b/drivers/scsi/imm.c
@@ -830,7 +830,7 @@
 
 		/* Phase 2 - We are now talking to the scsi bus */
 	case 2:
-		if (!imm_select(dev, cmd->device->id)) {
+		if (!imm_select(dev, scmd_id(cmd))) {
 			imm_fail(dev, DID_NO_CONNECT);
 			return 0;
 		}