Although you have not shown it in your question, you have clearly got another host function called Setzero
somewhere in your code. The simple solution is to rename the kernel to something else.
The underlying reason why the CUDA toolchain emits the error is because the Setzero<<< >>>
kernel invocation syntax in the runtime API causes the CUDA front end to create a host function of the same name as the kernel with a matching argument list and substitute the kernel launch for a call to that function. This host function contains the necessary API calls to launch the kernel. By having another host function with the same name as the kernel, you defeat this process and cause the compilation error you see.