net/tls: remove the dead inplace_crypto code

net/tls: remove the dead inplace_crypto code

Looks like when BPF support was added by commit 7f1e5e018bbc
("tls: add bpf support to sk_msg handling") and
commit 64f52bffa57f ("tls: convert to generic sk_msg interface")
it broke/removed the support for in-place crypto as added by
commit 5984df7abdc6 ("tls: Add support for inplace records
encryption").

The inplace_crypto member of struct tls_rec is dead, inited
to zero, and sometimes set to zero again. It used to be
set to 1 when record was allocated, but the skmsg code doesn't
seem to have been written with the idea of in-place crypto
in mind.

Since non trivial effort is required to bring the feature back
and we don't really have the HW to measure the benefit just
remove the left over support for now to avoid confusing readers.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>