Logger: avoid formatting for strings without additional args

[denizzzka]

At various software it is found very big amount of logger calls where is only single string variable used as an argument.

But if somewhere is logInfo(someGeneratedMsg); called and someGeneratedMsg contains % escape sequence it will be thrown exception.

PR fixes this issue.

[s-ludwig]

I was a bit worried about the silent acceptance of a possibly bad format string, but since we are just talking about logging, this really looks like just a theoretical concern.