staging: rtl8723bs: removed unused code block

Removed conditional code block checked by unused CONFIG_TX_BCAST2UNI

This patch does the cleaning required in TODO file:

find and remove code blocks guarded by never set CONFIG_FOO defines

Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/20210305191713.GA2466@agape.jhs


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