Use fromLocal8Bit for reversing toLocal8Bit

path is converted to 8-bit encoding using toLocal8Bit in
QTemporaryFileEngine::open. The reverse operation should be used here.
(cherry picked from commit 023976f9dd48a3deb947905d32d5fc0692da7318)

Change-Id: Idb4c1ca3415300367c46a09d68df640e17b7bfdc
Reviewed-by: João Abecasis <joao.abecasis@nokia.com>

src/corelib/io/qtemporaryfile.cpp

@@ -141,7 +141,7 @@ static int createFileFromTemplate(char *const path,
                 return -1;
         }
 #else
-        if (!QFileInfo(QLatin1String(path)).exists())
+        if (!QFileInfo(QString::fromLocal8Bit(path)).exists())
             return 1;
 #endif