Add break to switch in CompileDumpD8

Change-Id: I405587532b9c157d3211c33c3bb1cf244b8dc34e

src/main/java/com/android/tools/r8/utils/CompileDumpD8.java

diff --git a/src/main/java/com/android/tools/r8/utils/CompileDumpD8.java b/src/main/java/com/android/tools/r8/utils/CompileDumpD8.java
index 0e3a0c5..b2c4269 100644
--- a/src/main/java/com/android/tools/r8/utils/CompileDumpD8.java
+++ b/src/main/java/com/android/tools/r8/utils/CompileDumpD8.java
@@ -72,6 +72,7 @@
           case "--classfile":
             {
               outputMode = OutputMode.ClassFile;
+              break;
             }
           case "--debug":
             {