tls: rx: drop unnecessary arguments from tls_setup_from_iter()

[ Upstream commit d4bd88e6 ]

sk is unused, remove it to make it clear the function
doesn't poke at the socket.

size_used is always 0 on input and @length on success.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: f7fa16d4 ("tls: decrement decrypt_pending if no async completion will be called")
Signed-off-by: Sasha Levin <sashal@kernel.org>