fix openssl operations on non blocking socket

I was having problems with ossec-authd (SSL Accept error + SSL Read error). This was due to incorrect error handling for these two operations in the context of non blocking sockets (which is the case for the ossec-authd server).

I don't know what I seem to be the only one to experience this issue (maybe my LAN is particularly slow ... :/)
The diff contains a lot of noise because I removed a if/else construct, and then reindented a big block of code.

Orgianl Pull Request: https://bitbucket.org/jbcheng/ossec-hids/pull-request/26/fix-openssl-operations-on-non-blocking/diff 

@gaelmuller