Channel counts are uint32_t

Change-Id: I5676b6a291b72d7db6326f7eaf6d17588de51b05
diff --git a/services/audioflinger/AudioMixer.cpp b/services/audioflinger/AudioMixer.cpp
index 91aedbb..8bd04c6 100644
--- a/services/audioflinger/AudioMixer.cpp
+++ b/services/audioflinger/AudioMixer.cpp
@@ -566,7 +566,7 @@
                 resampler = AudioResampler::create(
                         format,
                         // the resampler sees the number of channels after the downmixer, if any
-                        downmixerBufferProvider != NULL ? MAX_NUM_CHANNELS : channelCount,
+                        (int) (downmixerBufferProvider != NULL ? MAX_NUM_CHANNELS : channelCount),
                         devSampleRate, quality);
                 resampler->setLocalTimeFreq(sLocalTimeFreq);
             }