Fixing issue llvm/hpvm#60: removing all warnings

llvm/projects/hpvm-tensor-rt/CMakeLists.txt

llvm/projects/hpvm-tensor-rt/dnn_sources/include/utils.h

...s/hpvm-tensor-rt/dnn_sources/src/half/lenet_mnist_half.cc

llvm/projects/hpvm-tensor-rt/dnn_sources/src/lenet_mnist.cc

llvm/projects/hpvm-tensor-rt/dnn_sources/src/unit_tests.cc

...jects/hpvm-tensor-rt/tensor_runtime/include/device_math.h

...hpvm-tensor-rt/tensor_runtime/include/functional/common.h

...ts/hpvm-tensor-rt/tensor_runtime/src/approx_simulation.cu

...projects/hpvm-tensor-rt/tensor_runtime/src/device_math.cu

...s/hpvm-tensor-rt/tensor_runtime/src/img_tensor_runtime.cu

...rojects/hpvm-tensor-rt/tensor_runtime/src/tensor_utils.cu