HID: intel-ish-hid: Drop if block with an always false condition

A remove callback is only ever called for a bound device. So there is no
need to check for device or driver being NULL.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>