I verified it with virt-viewer-2.0-17.el6.x86_64.
$ virt-viewer -c qemu:///system rhel7.2 --hotkeys=invalid
(virt-viewer:18800): virt-viewer-WARNING **: missing value for key 'invalid'
$ virt-viewer -c qemu:///system rhel7.2 --hotkeys=invalid=a
(virt-viewer:18827): virt-viewer-WARNING **: Unknown hotkey command invalid
From above logs, we can see no unnecessary smartcard logs display and the correct warning log display for incorrect hotkeys setting.
So move the bug from ON_QA to VERIFIED.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://rhn.redhat.com/errata/RHBA-2017-0587.html