staging: wlags49_h2: Do not use assignment in if condition

Fix the following checkpatch.pl issue in wl_netdev.c:
ERROR: do not use assignment in if condition

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