MINOR: mworker/cli: reload command displays the startup-logs

MINOR: mworker/cli: reload command displays the startup-logs

Change the output of the "reload" command, it now displays "Success=0"
if the reload failed and "Success=1" if it succeed.

If the startup-logs is available (USE_SHM_OPEN=1), the command will
print a "--\n" line, followed by the content of the startup-logs.

Example:

	$ echo "reload" | socat /tmp/master.sock -
	Success=1
	--
	[NOTICE]   (482713) : haproxy version is 2.7-dev7-4827fb-69
	[NOTICE]   (482713) : path to executable is ./haproxy
	[WARNING]  (482713) : config : 'http-request' rules ignored for proxy 'frt1' as they require HTTP mode.
	[NOTICE]   (482713) : New worker (482720) forked
	[NOTICE]   (482713) : Loading success.

	$ echo "reload" | socat /tmp/master.sock -
	Success=0
	--
	[NOTICE]   (482886) : haproxy version is 2.7-dev7-4827fb-69
	[NOTICE]   (482886) : path to executable is ./haproxy
	[ALERT]    (482886) : config : parsing [test3.cfg:1]: unknown keyword 'Aglobal' out of section.
	[ALERT]    (482886) : config : Fatal errors found in configuration.
	[WARNING]  (482886) : Loading failure!

	$