staging: vt6655: Rename function MACbSafeRxOff

Rename function MACbSafeRxOff to vt6655_mac_safe_rx_off to avoid
CamelCase which is not accepted by checkpatch.pl. Remove unnecessary
declaration of function and make function static.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/0cbcc7205e943393e2873839116d5ffcfb9d3d00.1662890990.git.philipp.g.hortmann@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>