net/bridge/br_multicast.c: fix: include/net/ipv6.h:362:27: warning: '*((void *)&ip+4)'& '*((void *)&ip+8)' may be used uninitialized in this function

Change-Id: I23a385f96fb87b6eab4d00829200b230378ef6d0
Signed-off-by: Dennis Rassmann <showp1984@gmail.com>