Break away from longer file extensions.

Missing "break" statements were causing us to match invalid file
extensions like "fpe."

Bug: 116751711
Test: /data/nativetest64/installd_utils_test/installd_utils_test
Change-Id: I250e9f16df998d50f5aaefb0d3a0f68fd5f73835
diff --git a/cmds/installd/matchgen.py b/cmds/installd/matchgen.py
index 131487d..42ce82b 100644
--- a/cmds/installd/matchgen.py
+++ b/cmds/installd/matchgen.py
@@ -84,6 +84,8 @@
                 print "%scase '%s':" % (prefix, k)
             dump(target[k], index + 1)
     print "%s}" % (prefix)
+    if index > 0:
+        print "%sbreak;" % (prefix)
 
 dump(trie, 0)