[openib-general] SA multicast patches

[Sean Hefty]

> Or is it that you want to be able to iterate through the whole rbtree
> and get the MGID 0 groups too?

This is it - see mcast_groups_lost().  That call transitions all multicast 
groups into an error state, and reports to the user that the group information 
may have been lost by the SA.  (We can't trust that a successful join response 
is still valid, even if it is reported after we receive a fatal event.)

- Sean