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/remotelinux/linuxdevicetester.cpp

@@ -226,8 +226,8 @@ void GenericLinuxDeviceTester::testRsync()
         if (d->rsyncProcess.error() == QProcess::FailedToStart)
             handleRsyncFinished();
     });
-    connect(&d->rsyncProcess, static_cast<void (QProcess::*)(int)>(&QProcess::finished),
-            [this] {
+    connect(&d->rsyncProcess, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
+            this, [this] {
         handleRsyncFinished();
     });
     const RsyncCommandLine cmdLine = RsyncDeployStep::rsyncCommand(*d->connection);