init: Fix infinite wait loop

Since waitpid always sends a SIGCHLD now, we'd handle a SIGCHLD after returning from waitpid, which would trigger another wait, looping forever and not actually handling the wait.

system/init.cpp

@@ -426,8 +426,6 @@ Result<int> luna_main(int argc, char** argv)
                               "change the default service path (/etc/init or /etc/user)");
     parser.parse(argc, argv);
 
-    signal(SIGCHLD, wait_for_child);
-
     if (user) return user_init(service_path);
     return sysinit(service_path);
 }