HID: wacom: Do not repeatedly attempt to set device mode on error

As an extension of aef3156d, there is no sense in repeatedly calling the
'wacom_set_report' and 'wacom_get_report' functions if they return an
error. Getting an error from them implies that the device is out to lunch:
either a hard error code was returned or repeated attempts at recovering
from a "soft" error all failed. In either case, doing even more retries is
not likely to resolve whatever is wrong.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>