fixed small bug which could lead to segfaults in opencl.
fixed small bug which could lead to segfaults in opencl.

ShibataLab/iai_kinect2,MRASL/iai_kinect2,code-iai/iai_kinect2,personalrobotics/iai_kinect2,code-iai/iai_kinect2,code-iai/iai_kinect2,personalrobotics/iai_kinect2,ShibataLab/iai_kinect2,MRASL/iai_kinect2