fallout of cleaning-up libutils includes

Test: run & compile
Bug: n/a
Change-Id: I63585ed5a764b9ce7af2187b79ca0c83e683fd7f
diff --git a/media/libnbaio/PipeReader.cpp b/media/libnbaio/PipeReader.cpp
index bd468a6..be5c0c1 100644
--- a/media/libnbaio/PipeReader.cpp
+++ b/media/libnbaio/PipeReader.cpp
@@ -18,6 +18,7 @@
 //#define LOG_NDEBUG 0
 
 #include <cutils/compiler.h>
+#include <cutils/atomic.h>
 #include <utils/Log.h>
 #include <media/nbaio/PipeReader.h>