Reset waits when terminating a thread.

Terminated threads can't be waiting.

Core/HLE/sceKernelThread.cpp

@@ -1738,6 +1738,10 @@ void __KernelStopThread(SceUID threadID, int exitStatus, const char *reason)
 			}
 		}
 		t->waitingThreads.clear();
+
+		// Stopped threads are never waiting.
+		t->nt.waitType = WAITTYPE_NONE;
+		t->nt.waitID = 0;
 	}
 	else
 		ERROR_LOG_REPORT(SCEKERNEL, "__KernelStopThread: thread %d does not exist", threadID);