Kernel: Fix gcc warning about narrowing conversion

Fix gcc 4.7.1 warning: 'narrowing conversion of 'value' from 'int' to
'uint {aka unsigned int}' inside { } is ill-formed in C++11 '

Change-Id: I64ee1a35ecd60cc6a5d7d024c5f903078b3d4f60
Reviewed-by: Qt Doc Bot <qt_docbot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

src/corelib/kernel/qcoreapplication_win.cpp

@@ -522,7 +522,7 @@ struct FLAG_STRING_STRUCT
     const char* str;
 };
 
-FLAG_STRING_STRUCT FLAG_STRING(int value = 0, const char *c = 0)
+FLAG_STRING_STRUCT FLAG_STRING(uint value = 0, const char *c = 0)
 {
     FLAG_STRING_STRUCT s = {value, c};
     return s;