Added check to qtemporarydir unittest to check and skip if root

- nonWritableCurrentDir() function not valid test when run as root
  on unix platform so add skip.

Change-Id: I0c5ee685d3bdeaf3d5d2e0bb93ba7d7796fd1028
Reviewed-by: Kurt Korbatits  <kurt.korbatits@nokia.com>
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>

tests/auto/corelib/io/qtemporarydir/tst_qtemporarydir.cpp

@@ -228,6 +228,9 @@ void tst_QTemporaryDir::autoRemove()
 void tst_QTemporaryDir::nonWritableCurrentDir()
 {
 #ifdef Q_OS_UNIX
+    if (::geteuid() == 0)
+        QSKIP("not valid running this test as root");
+
     struct ChdirOnReturn
     {
         ChdirOnReturn(const QString& d) : dir(d) {}