NFC: fix possible resource leak

Put the device to avoid resource leak on path that the polling flag is
invalid.

Fixes: a831b913

 ("NFC: Do not return EBUSY when stopping a poll that's already stopped")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Link: https://lore.kernel.org/r/20210121153745.122184-1-bianpan2016@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>