staging: rtl8723bs: change return type to bool

Both rtw_is_cckrates_included() and rtw_is_cckratesonly_included()
return true or false. Change the return type from uint to bool.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>