zd1211rw: Fix multicast filtering.
zd1211rw: Fix multicast filtering.

If multicast parameter (as returned by zd_op_prepare_multicast) has
changed, no bit in changed_flags is set. To handle this situation, we do
not return if changed_flags is 0. If we do so, we will have some issue
with IPv6 which uses multicast for link layer address resolution.

Signed-off-by: Benoit Papillault <8991e311035067725ffdc82cfef219cbbb0a30fd@free.fr>
Signed-off-by: John W. Linville <2a53bac7a5d324865ef46ec4c38b2c0fba1456b4@tuxdriver.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas