audio: Fix clang warnings

Generally these warnings come from -Wformat

Test: compiles
Bug: 324511705
Change-Id: I6129b0793e2aa85e9a2b407c473c766f61122d1b
diff --git a/media/libnbaio/SourceAudioBufferProvider.cpp b/media/libnbaio/SourceAudioBufferProvider.cpp
index d58619f..157ebd7 100644
--- a/media/libnbaio/SourceAudioBufferProvider.cpp
+++ b/media/libnbaio/SourceAudioBufferProvider.cpp
@@ -32,7 +32,7 @@
     // negotiate with source
     NBAIO_Format counterOffers[1];
     size_t numCounterOffers = 1;
-    ssize_t index = source->negotiate(NULL, 0, counterOffers, numCounterOffers);
+    [[maybe_unused]] ssize_t index = source->negotiate(NULL, 0, counterOffers, numCounterOffers);
     ALOG_ASSERT(index == (ssize_t) NEGOTIATE && numCounterOffers > 0);
     numCounterOffers = 0;
     index = source->negotiate(counterOffers, 1, NULL, numCounterOffers);