[auto-discovery][jmx] write SD pipe terminator.

[auto-discovery] typo in terminator.

agent.py

@@ -74,6 +74,7 @@
 JMX_GRACE_SECS = 2
 SERVICE_DISCOVERY_PREFIX = 'SD-'
 SD_CONFIG_SEP = "#### SERVICE-DISCOVERY ####\n"
+SD_CONFIG_TERM = "#### SERVICE-DISCOVERY TERM ####\n"
 
 DEFAULT_SUPERVISOR_SOCKET = '/opt/datadog-agent/run/datadog-supervisor.sock'
 DEFAULT_COLLECTOR_PROFILE_INTERVAL = 20
@@ -450,6 +451,7 @@ def _submit_jmx_service_discovery(self, jmx_sd_configs):
                 # will block if len(buffer) > OS pipe buffer.
                 # JMX will unblock when it reads on the other end.
                 os.write(self.sd_pipe, buffer)
+                os.write(self.sd_pipe, SD_CONFIG_TERM)
         except Exception as e:
             log.exception("unable to submit YAML via pipe: %s", e)
         else: