Session leaking resulting from random ISID use

[geek]

According to https://tools.ietf.org/html/rfc3720#section-5.3.5 and https://tools.ietf.org/html/rfc3720#section-9.1.1 there should be some reuse of an ISID. The reuse is needed for situations like a timeout where libiscsi closes the connection and needs to reinstate the previous session, but indicate to the target that the old connection session is no longer valid.

The current behavior is that a reconnect will generate a random ISID.

As a result, any reconnect will cause a target to retain sessions that are no longer valid.

Let me know if you think this is a valid issue. Also, if you have any suggestions on how to fix I can try and help fix if needed. Thanks.