drm: fix build failure and misc .clang-format issue

drm_log relies on -Wgnu-zero-variadic-macro-arguments ignored.

Fixes: 060f4481 ("drm: Silence GCC warnings")
Signed-off-by: Yiwei Zhang <zzyiwei@chromium.org>
Part-of: <https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/1165>
2 files changed