tls: rx: fix the NoPad getsockopt

Maxim reports do_tls_getsockopt_no_pad() will
always return an error. Indeed looks like refactoring
gone wrong - remove err and use value.

Reported-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Fixes: 88527790 ("tls: rx: add sockopt for enabling optimistic decrypt with TLS 1.3")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>