Call ring_trans synchronously, not in a spawn
Call ring_trans synchronously, not in a spawn

Calling `add_supported_to_ring` is not threadsafe.
If a process retrieves the member_meta and then
it's concurrently updated by another process,
the original process' changed will be overwritten.

To exhibit the original bug, I added a
timer:sleep(crypto:rand_uniform(1, 1000))
line inside the spawned fun that calls
riak_core_ring_manager:ring_trans(F, ok)

Kyorai/riak_core