Fix incorrect switch for IF_TYPE in part.c

Use correct field in block_dev_desc_t when writing interface type in
dev_print. Error introduced in 574b3195.

Also added fix from Martin Krause

Signed-off-by: Tor Krill <tor@excito.com>
diff --git a/disk/part.c b/disk/part.c
index 316e254..5c4bf6b 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -109,7 +109,7 @@
 	lbaint_t lba512;
 #endif
 
-	switch (dev_desc->type) {
+	switch (dev_desc->if_type) {
 	case IF_TYPE_SCSI:
 		printf ("(%d:%d) Vendor: %s Prod.: %s Rev: %s\n",
 			dev_desc->target,dev_desc->lun,
@@ -124,7 +124,7 @@
 			dev_desc->revision,
 			dev_desc->product);
 		break;
-	case DEV_TYPE_UNKNOWN:
+	case IF_TYPE_UNKNOWN:
 	default:
 		puts ("not available\n");
 		return;