Merge branch 'remove-unused-support-for-crypto-tfm-cloning'

Eric Biggers says:

====================
Remove unused support for crypto tfm cloning

This series is targeting net-next because it depends on
"net/tcp: Remove tcp_sigpool".  So far no commits in cryptodev conflict
with this, so I suggest that this be taken through net-next for 7.2.

This series removes support for transformation cloning from the crypto
API.  Now that the TCP-AO and TCP-MD5 code no longer uses it, it no
longer has a user.  And it's unlikely that a new one will appear, as the
library API solves the problem in a much simpler and more efficient way.

This feature also regressed performance for all crypto API users, since
it changed crypto transformation objects into reference-counted objects.
That added expensive atomic operations.  The refcount is reverted by
this series, thus fixing the performance regression.

A subset of this was previously sent in
https://lore.kernel.org/r/20260307224341.5644-1-ebiggers@kernel.org
Compared to that version, this version is a bit more comprehensive.
====================

Link: https://patch.msgid.link/20260522053028.91165-1-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>