NA CCI: Added error handling when cci_connect() fails

[marcvef]

When na_cci_addr_lookup() is eventually called from HG_Addr_lookup(), the function cci_connect() can return an error which is currently not handled. As a result, clients receive HG_SUCCESS when calling HG_Addr_lookup() although it has failed. This patch returns the appropriate error message for two cases: (1) cci_connect() timed out, or (2) other errors.

We faced this situation, while using CCI with the verbs plugin, when many clients called HG_Addr_lookup() to the same servers, essentially overwhelming the server to respond in time. The following error message was produced on the client side, with HG_Addr_lookup() returning HG_SUCCESS:

 # na_cci_addr_lookup(): cci_connect(verbs://a0357-ib:4433) failed with CCI_ETIMEDOUT
# NA -- Error -- /some/path/mercury/src/na/na_cci.c:833

Note, that cci_connect() can be given an optional timeout value (currently set to NULL in na_cci_addr_lookup(), i.e., wait forever according to documentation), which is not used in cci_connect().

[soumagne]

Interesting, thanks! I'll go through it and merge it.