use the command 'clear_errors' to return from an error state
+ make sure target is valid after clear_errors
Change-Id: I3c180500a05836d52bbb9a8ecbdb397adea03d0d
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/31337
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>