Remove bogus attempt to simulate scrolling. It's not needed and messes up serial output.

[imp]

Summary

So the 'always set the cursor position' has a problem.

On serial console, it mixes escape codes and characters needlessly.
It also causes the serial console to bogusly scroll one line when it overflows the screen

These changes allow the device to cope on its own w/o trying to second guess itself.
It isn't perfect, but it's a lot better.