[media] media: video: pvrusb2: fix memory leak

Use put_device() instead of kfree() because of device name leak.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>