staging: wlags49_h2: Enclose macro in a do-while loop

Fix the following checkpatch.pl issues in wl_netdev.c:
ERROR: Macros with multiple statements should be enclosed in a do -
while loop

Signed-off-by: Jelena Bjelja <jelena.bjelja.ing@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>