set_password command of monitor has poor feedback on failure

[Karl-Philipp Richter]

running `set_password vnc NkkmEz5icvTAGo6MECzBVEUxP` in qemu monitor (which is the appropriate way to set a vnc password according to `man qemu-system-x86_64`) started with `-monitor stdio` gives feedback `Could not set password` which is unhelpful because it doesn't specify the reason of the failure.

experienced with 2.3.0

[Thomas Huth (th-huth)]

The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]