HID: wacom: Only report rotation for art pen

HID: wacom: Only report rotation for art pen

commit de0dfa8310c9f04f5b43bfea943180d4d80314e6 upstream.

The generic routine, wacom_wac_pen_event, turns rotation value 90
degree anti-clockwise before posting the events. This non-zero
event trggers a non-zero ABS_Z event for non art pen tools. However,
HID_DG_TWIST is only supported by art pen.

[jkosina@suse.cz: fix build: add missing brace]
Cc: stable@vger.kernel.org
Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
Reviewed-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>