HID: wacom: Improve warning for tablets falling back to default resolution

When we encounter a usage mapped to ABS_X or ABS_Y which has a calculated
resolution of 0, we want to warn the user of this before setting a default
value. The previous language used the word "usage" but then printed out the
value of a "code" instead. We can improve this.

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