Fix deadlock caused by a race condition in the logger when reloading (issue #7195 reported and fixed by softins)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@30033 65c4cc65-6c06-0410-ace0-fbb531ad65f3

logger.c

@@ -384,6 +384,7 @@ int reload_logger(int rotate)
 	FILE *myf;
 	int x, res = 0;
 
+	ast_mutex_lock(&msglist_lock);	/* to avoid deadlock */
 	ast_mutex_lock(&loglock);
 	if (eventlog) 
 		fclose(eventlog);
@@ -490,6 +491,7 @@ int reload_logger(int rotate)
 		}
 	}
 	ast_mutex_unlock(&loglock);
+	ast_mutex_unlock(&msglist_lock);
 
 	return res;
 }