audio policy: fix typo in doReleaseOutput()

Fix use use of mAudioRecordClients instead of
mAudioPlaybackClients in doReleaseOutput().

Test: make.
Change-Id: I5c695582828300c0297f4f58bcba37e17b51bbbd
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index 93e3c44..9a39275 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -322,7 +322,7 @@
         return;
     }
     sp<AudioPlaybackClient> client = mAudioPlaybackClients.valueAt(index);
-    mAudioRecordClients.removeItem(portId);
+    mAudioPlaybackClients.removeItem(portId);
 
     // called from internal thread: no need to clear caller identity
     mAudioPolicyManager->releaseOutput(portId);