Force the kill of the "nc" process only if timeout

If the file is received correctly, the "nc" process in the remote
machine will end gracefully. Only in case of socket timeout, will force
the completion of the process before returning.

Change-Id: I6cec868daa0139f6a49807883f901d2eac84fe14
Related-Bug: #1838068
diff --git a/neutron_tempest_plugin/scenario/test_qos.py b/neutron_tempest_plugin/scenario/test_qos.py
index 13a06ae..82a5391 100644
--- a/neutron_tempest_plugin/scenario/test_qos.py
+++ b/neutron_tempest_plugin/scenario/test_qos.py
@@ -130,10 +130,10 @@
         except socket.timeout:
             LOG.warning('Socket timeout while reading the remote file, bytes '
                         'read: %s', total_bytes_read)
+            self._kill_nc_process(ssh_client)
             return False
         finally:
             client_socket.close()
-            self._kill_nc_process(ssh_client)
 
     def _create_ssh_client(self):
         return ssh.Client(self.fip['floating_ip_address'],