[ofiwg] RFC on error handling in fi_getinfo call

[Hefty, Sean]

OFI has an fi_getinfo call, which is similar to rdma_getaddrinfo and getaddrinfo.  It's used to query which endpoints are supported by the underlying providers.  There's been discussion on github threads on how the call should behave in the presence of errors.  Without changing the API, there are 2 basic choices.

1. If any provider fails unexpectedly (i.e. any error other than ENODATA), the entire call fails.  The error is returned to the application.

2. If a provider fails, the failure is skipped.  Any attributes gathered from other providers are returned.

There are pros/cons to both, and wider community feedback is needed.

- Sean