Recognise broken SMB sessions and close them

[smashery]

If an SMB session is forcibly closed or inoperative, the session remained in the list of open sessions (until forcibly closed). This recognises certain errors and shuts the SMB sessions down.

Verification

• Start msfconsole
• Create several sessions with the smb_login module onto the one host
• Shut down the server (this won't cause the sessions to terminate yet)
• Run a module with an SMB session (any of the ones that use SMB optional sessions)
• Verify that it is terminated, and removed from the list of active sessions

Demo

msf6 auxiliary(scanner/smb/pipe_auditor) > run session=3
[*] Using existing session 3
[*] 192.168.20.99 - SMB session 3 closed.
[*] Error: 192.168.20.99: RubySMB::Error::CommunicationError An error occurred writing to the Socket: Connection reset by peer
[*] Scanned 1 of 1 hosts (100% complete)
[*] Auxiliary module execution completed