We don't need __STDC_FORMAT_MACROS any more.

Test: treehugger
Change-Id: Iada8b959f61bfa55b61d2ed4b345801ed9cea0c6
diff --git a/libutils/StopWatch.cpp b/libutils/StopWatch.cpp
index c88d60f..c91cd5c 100644
--- a/libutils/StopWatch.cpp
+++ b/libutils/StopWatch.cpp
@@ -18,10 +18,6 @@
 
 #include <utils/StopWatch.h>
 
-/* for PRId64 */
-#ifndef __STDC_FORMAT_MACROS
-#define __STDC_FORMAT_MACROS 1
-#endif
 #include <inttypes.h>
 
 #include <log/log.h>