[ofiwg] input on which error codes to pass through 'sread' calls

[Hefty, Sean]

This query is in response to the following pull request:

https://github.com/ofiwg/libfabric/pull/4829

The specific question is should libfabric convert an error code of EINTR to EAGAIN for any blocking read call, e.g. fi_cq_sread?

The current behavior traps for ETIMEDOUT and converts that to EAGAIN.  An argument could be made to also convert EINTR.  That opens the possibility that other select error codes should be converted as well for any sread call.

An argument for makings this conversion is that some apps only check for EAGAIN, and EINTR would not be considered a fatal error.

- Sean