ieee1394: csr1212: warn on unreachable code

We want bugs to show themselves.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/ieee1394/csr1212.c b/drivers/ieee1394/csr1212.c
index 63bf11e..3c044fc 100644
--- a/drivers/ieee1394/csr1212.c
+++ b/drivers/ieee1394/csr1212.c
@@ -772,6 +772,7 @@
 
 		default:
 			/* Should never get here */
+			WARN_ON(1);
 			break;
 		}
 
@@ -852,7 +853,8 @@
 				break;
 			default:
 				/* Should never get here */
-				break; /* GDB breakpoint */
+				WARN_ON(1);
+				break;
 			}
 
 			value |= (a->key.id & CSR1212_KV_KEY_ID_MASK) <<
@@ -889,7 +891,8 @@
 		case CSR1212_KV_TYPE_IMMEDIATE:
 		case CSR1212_KV_TYPE_CSR_OFFSET:
 			/* Should never get here */
-			break; /* GDB breakpoint */
+			WARN_ON(1);
+			break;
 
 		case CSR1212_KV_TYPE_LEAF:
 			/* Don't copy over Extended ROM areas, they are