Correct a fp with this exploit module (would always print success)

modules/exploits/linux/ssh/f5_bigip_known_privkey.rb

@@ -96,6 +96,7 @@ class Metasploit3 < Msf::Exploit::Remote
 		rescue Rex::ConnectionError, Rex::AddressInUse
 			return :connection_error
 		rescue Net::SSH::Disconnect, ::EOFError
+			print_error "#{rhost}:#{rport} SSH - Disconnected during negotiation"
 			return :connection_disconnect
 		rescue ::Timeout::Error
 			print_error "#{rhost}:#{rport} SSH - Timed out during negotiation"
@@ -120,11 +121,9 @@ class Metasploit3 < Msf::Exploit::Remote
 
 	def exploit
 		conn = do_login("root")
-		if conn
+		if conn.class == Net::SSH::CommandStream
 			print_good "Successful login"
 			handler(conn.lsock)
-		else
-			print_error "Login failed"
 		end
 	end