suspended() and isSuspended() are const

Change-Id: I04b95970b5a645b64e7e64fffd46d868354dda66
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 8255823..b22c3ea 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -6702,7 +6702,8 @@
     Mutex::Autolock _l(mLock);
     mSuspended = suspended;
 }
-bool AudioFlinger::EffectModule::suspended()
+
+bool AudioFlinger::EffectModule::suspended() const
 {
     Mutex::Autolock _l(mLock);
     return mSuspended;