MsvcToolChain: Convert paths in fromMap

We used to store those paths as they were writen in the registry with
'\'. That was changed in edb13dd3

Task-number: QTCREATORBUG-8951
Change-Id: I63e5218faab87ebe8215bad773eb943cd9f8f074
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/projectexplorer/msvctoolchain.cpp

@@ -384,7 +384,7 @@ bool MsvcToolChain::fromMap(const QVariantMap &data)
 {
     if (!ToolChain::fromMap(data))
         return false;
-    m_vcvarsBat = data.value(QLatin1String(varsBatKeyC)).toString();
+    m_vcvarsBat = QDir::fromNativeSeparators(data.value(QLatin1String(varsBatKeyC)).toString());
     m_varsBatArg = data.value(QLatin1String(varsBatArgKeyC)).toString();
     const QString abiString = data.value(QLatin1String(supportedAbiKeyC)).toString();
     m_abi = Abi(abiString);