ipv6: fix unappropriate errno returned for non-multicast address
ipv6: fix unappropriate errno returned for non-multicast address

We need to check the passed in multicast address and return
appropriate errno(EINVAL) if it is not valid. And it's no need
to walk through the ipv6_mc_list in this situation.

Signed-off-by: Li Wei <b1e2e3ae26f1849f6f819475f53ed1fe23965c50@cn.fujitsu.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

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