Input: evdev - get rid of old workaround for EVIOCGBIT

We put this workaround in 2008 and the offending userspace has been fixed
up long time ago; the link in the message is no longer valid either, so it
is time to retire it.

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>