Fix some simple checkpatch.pl warnings in rc4030.c.

Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Aleksandar Rikalo <arikalo@wavecomp.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <1561472838-32272-3-git-send-email-aleksandar.markovic@rt-rk.com>