qmp_deserialize() calls qobject_from_json() ignoring errors.  It
passes the result to qobject_input_visitor_new(), which asserts it's
not null.  Therefore, we can just as well pass &error_abort to
qobject_from_json().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-16-git-send-email-armbru@redhat.com>