audiopolicy: Remove ; after namespace bracket

Semicolons are not needed after the closing bracket of
a namespace, remove it.

Test: compiles
Change-Id: Ie82930365f738fd9c95a9163839a68b772e49d95
diff --git a/services/audiopolicy/engine/interface/AudioPolicyManagerObserver.h b/services/audiopolicy/engine/interface/AudioPolicyManagerObserver.h
index 846fa48..b7902cf 100644
--- a/services/audiopolicy/engine/interface/AudioPolicyManagerObserver.h
+++ b/services/audiopolicy/engine/interface/AudioPolicyManagerObserver.h
@@ -59,4 +59,4 @@
     virtual ~AudioPolicyManagerObserver() {}
 };
 
-}; // namespace android
+} // namespace android