staging: rtl8723bs: Wrap multi-line macros in do-while loop

Wrapping in do-while ensures macros are executed as expected.

Signed-off-by: Justin Vreeland <justin@jvreeland.com>
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>