Don't count BTN_TOUCH as tool. (#29428)

Devices that don't have a tool but BTN_TOUCH simply have the tool always on.
Devices that have a tool other than BTN_TOUCH set this tool before BTN_TOUCH
is emitted anyway.

X.Org Bug 29428 <http://bugs.freedesktop.org/show_bug.cgi?id=29428>

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/evdev.c

@@ -577,7 +577,6 @@ EvdevProcessKeyEvent(InputInfoPtr pInfo, struct input_event *ev)
             break;
 
         case BTN_TOUCH:
-            pEvdev->tool = value ? ev->code : 0;
             if (!(pEvdev->flags & (EVDEV_TOUCHSCREEN | EVDEV_TABLET)))
                 break;
             /* Treat BTN_TOUCH from devices that only have BTN_TOUCH as