Replace static_casts by QOverload where possible

Mainly to get rid of the QProcess::finished deprecation warning.

Also adjust coding style in the surrounding connects when needed.

Change-Id: I12f9b248c7974b892c4a069356e578e80f8c59e9
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/qmakeprojectmanager/externaleditors.cpp

@@ -288,8 +288,7 @@ bool DesignerExternalEditor::startEditor(const QString &fileName, QString *error
         m_processCache.insert(binary, socket);
         auto mapSlot = [this, binary] { processTerminated(binary); };
         connect(socket, &QAbstractSocket::disconnected, this, mapSlot);
-        connect(socket,
-                static_cast<void (QAbstractSocket::*)(QAbstractSocket::SocketError)>(&QAbstractSocket::error),
+        connect(socket, QOverload<QAbstractSocket::SocketError>::of(&QAbstractSocket::error),
                 this, mapSlot);
     }
     return true;