Fixed some checkpatch issues in ringbuf.c
Signed-off-by: NKang Minchul <tegongkang@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20221113190648.38556-4-tegongkang@gmail.com