staging: rtl8723bs: remove unused RT_PRINTK macro

remove unused RT_PRINTK macro definition.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/edf86e39fce8a53f52c8c8463d134ea426f58b60.1619794331.git.fabioaiuto83@gmail.com


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