radeon: Fix multiple definition error with radeon_debug

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3488>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3488>
2 files changed