bridge: re-introduce 'fix parsing of MLDv2 reports'

bridge: re-introduce 'fix parsing of MLDv2 reports'

commit a24b9270a178 ("bridge: multicast: treat igmpv3 report with
INCLUDE and no sources as a leave") seems to have accidentally reverted
commit 5352f25b108c ("bridge: fix parsing of MLDv2 reports"). This
commit brings back a change to br_ip6_multicast_mld2_report() where
parsing of MLDv2 reports stops when the first group is successfully
added to the MDB cache.

Fixes: a24b9270a178 ("bridge: multicast: treat igmpv3 report with INCLUDE and no sources as a leave")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>