Avoid naming clashes with QStringLiteral local variable

MSVC 2013 complains about the use of 's' if a variable 's' is already
defined in the context:

error C2373: 's' : redefinition; different type modifiers
error C3493: 's' cannot be implicitly captured because no default capture
mode has been specified

This looks like a compiler bug. Anyhow, it's easy to avoid the clash in
most cases by using a more distinctive name ...

Task-number: QTBUG-41706
Change-Id: Iaff1b6d37897fa8cf9e4913effa0498f9fd7bb07
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qstring.h

 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -167,8 +167,8 @@ Q_STATIC_ASSERT_X(sizeof(qunicodechar) == 2,
             Q_STATIC_STRING_DATA_HEADER_INITIALIZER(Size), \
             QT_UNICODE_LITERAL(str) }; \
         QStringDataPtr holder = { qstring_literal.data_ptr() }; \
-        const QString s(holder); \
-        return s; \
+        const QString qstring_literal_temp(holder); \
+        return qstring_literal_temp; \
     }()) \
     /**/