Drop double-semicolon in C

The worst offenders are "continue;;" and "break;;" in switch statements.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/tree.c b/tree.c
index dfe4d5f..25d2e29 100644
--- a/tree.c
+++ b/tree.c
@@ -110,7 +110,7 @@
 		case 0:
 			continue;
 		case READ_TREE_RECURSIVE:
-			break;;
+			break;
 		default:
 			return -1;
 		}