HID: roccat: silence an uninitialized variable warning

My static checker complains because we use "dev_id" before we check for
errors so it could be uninitialized.  Fix this by moving the error
handling forward a couple lines.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>