Fix leak in OpenCL ireduce
Fix leak in OpenCL ireduce

umar456/arrayfire,9prady9/arrayfire,umar456/arrayfire,arrayfire/arrayfire,9prady9/arrayfire,9prady9/arrayfire,arrayfire/arrayfire,9prady9/arrayfire,umar456/arrayfire,arrayfire/arrayfire,arrayfire/arrayfire,umar456/arrayfire