[CUDA] Fix issue with PTX files not being closed properly
[CUDA] Fix issue with PTX files not being closed properly

rjodin/pocl,rjodin/pocl,Oblomov/pocl,pocl/pocl,rjodin/pocl,jrprice/pocl,pocl/pocl,franz/pocl,rjodin/pocl,Oblomov/pocl,pocl/pocl,franz/pocl,franz/pocl,franz/pocl,franz/pocl,pocl/pocl,jrprice/pocl,jrprice/pocl,pocl/pocl,Oblomov/pocl,jrprice/pocl,Oblomov/pocl,Oblomov/pocl