staging: rtl8723bs: remove duplicate name for _rtw_write_port()

_rtw_write_port() is being redefined as rtw_write_port(). Because
rtw_write_port() is the only name used in the driver, remove the
duplicate definition and rename the function from _rtw_write_port()
to rtw_write_port()

Signed-off-by: Bryan Brattlof <hello@bryanbrattlof.com>
Link: https://lore.kernel.org/r/5b8543127a774ca65595588711c05cce28b17bf6.1621361919.git-series.hello@bryanbrattlof.com


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