logger: Add PID to syslog messages.

During refactoring of this support the addition of
the PID to messages was removed. This change adds it
back in.

ASTERISK-25538 #close

Change-Id: Ie2d43b0652e59b7ac319a7dba94501540d70ba36

main/logger.c

@@ -316,6 +316,7 @@ static struct logchannel *make_logchannel(const char *channel, const char *compo
 
 		chan->type = LOGTYPE_SYSLOG;
 		ast_copy_string(chan->filename, channel, sizeof(chan->filename));
+		openlog("asterisk", LOG_PID, chan->facility);
 	} else {
 		const char *log_dir_prefix = "";
 		const char *log_dir_separator = "";