Remove a duplicated call to QFile::open

File was opened on the previous line.

Change-Id: I418d616a2f82d9241c37224e4c1a0fb12894eb40
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

tests/auto/widgets/dialogs/qfiledialog2/tst_qfiledialog2.cpp

@@ -1110,7 +1110,6 @@ void tst_QFileDialog2::task254490_selectFileMultipleTimes()
     QTemporaryFile *t;
     t = new QTemporaryFile;
     QVERIFY2(t->open(), qPrintable(t->errorString()));
-    t->open();
     QFileDialog fd(0, "TestFileDialog");
 
     fd.setDirectory(tempPath);