Assign function argument to class member, not to itself

The 'worker' function argument shadows the class member of the same
name, and 'worker = worker;' assigns the function argument to itself,
not to the member as intended.

examples/tutorials/threads/movedobject/thread.cpp:69: warning:
explicitly assigning a variable of type 'QObject *' to itself [-Wself-
    worker = worker;
    ~~~~~~ ^ ~~~~~~

Change-Id: If4adf486a86a4ba4e7f7040a7771a70b7dd9aa86
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

examples/tutorials/threads/movedobject/thread.cpp

@@ -66,7 +66,7 @@ Thread::~Thread()
 // starts thread, moves worker to this thread and blocks
 void Thread::launchWorker(QObject *worker)
 {
-    worker = worker;
+    this->worker = worker;
     start();
     worker->moveToThread(this);
     shutDownHelper->moveToThread(this);