chrono: avoid possible invocation of explicit duration constructor

This avoids an issue with g++-4.8.



git-svn-id: http://wg11.sc29.org/svn/repos/MPEG-I/Part5-PointCloudCompression/TM/TMC3/trunk@1338 94298a81-5874-47c9-aab8-bfb24faeed7f

tmc3/pcc_chrono.h

@@ -93,7 +93,7 @@ public:
 
 private:
   typename Clock::time_point start_time_;
-  duration cumulative_time_ {0};
+  duration cumulative_time_ {duration::zero()};
 };
 }}