Add user_context to debug calls in copy_to_host_already_locked.
Add user_context to debug calls in copy_to_host_already_locked.


Former-commit-id: e27cc016f2d94ada472d16866a29f9da9d17f781
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide