IB/core: Fix RoCE v1 multicast join logic issue

During multicast join of RoCEv1, IGMP join state and max hop limit
were updated incorrectly. IGMP join should be sent and marked as
joined only on RoCEv2 after a successful join. Max hops should be
updated to the hop limit on RoCEv2 regardless of the join state.

Fixes: bee3c3c9 ('IB/cma: Join and leave multicast groups...')
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>