tools: ratbagc - allow for the device to be just 'event7'

ratbagctl requires 'eventX' as argument, but ratbag-command requires
/dev/input/eventX. That's not smart, let's do better.

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

tools/ratbagc.py.in

@@ -188,6 +188,9 @@ class Ratbagd(object):
 
     def __getitem__(self, id):
         """Returns the requested device, or None."""
+        if id.startswith("event"):
+            id = "/dev/input/{}".format(id)
+
         if id not in self._devices.keys():
             try:
                 dev = RatbagdDevice(self._ratbag, id)