nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done

nfc: fix potential NULL pointer deref in nfc_genl_dump_ses_done

commit 4cd8371a234d051f9c9557fcbb1f8c523b1c0d10 upstream.

The done() netlink callback nfc_genl_dump_ses_done() should check if
received argument is non-NULL, because its allocation could fail earlier
in dumpit() (nfc_genl_dump_ses()).

Fixes: ac22ac466a65 ("NFC: Add a GET_SE netlink API")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211209081307.57337-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>