dynamicobject: keep the value on the return value alive when tracing
dynamicobject: keep the value on the return value alive when tracing

Change-Id: I546e8ea3a0817d721b38ea13ad4648677d179cb2
Reviewed-on: http://gerrit.aldebaran.lan/27342
Reviewed-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>
Tested-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>

aldebaran/libqi,aldebaran/libqi,vbarbaresi/libqi,bsautron/libqi,aldebaran/libqi