tests/multi_net: Close accepted sockets when tests are done.

gc_sweep_all() cleans up sockets via the finaliser, but tests should
cleanly free resources they use.

tests/multi_net/ssl_data.py

@@ -47,6 +47,7 @@ def instance0():
     s2 = ssl.wrap_socket(s2, server_side=True, key=key, cert=cert)
     print(s2.read(16))
     s2.write(b"server to client")
+    s2.close()
     s.close()
 
 

tests/multi_net/tcp_client_rst.py

@@ -38,6 +38,7 @@ def instance0():
     # TODO lwip raises here but apparently it shouldn't
     print(s2.recv(10))
     print(convert_poll_list(poll.poll(1000)))
+    s2.close()
     s.close()
 
 

tests/multi_net/tcp_data.py

@@ -15,6 +15,7 @@ def instance0():
     s2, _ = s.accept()
     print(s2.recv(16))
     s2.send(b"server to client")
+    s2.close()
     s.close()