ktls: Remove the socket parameter to ktls_ocf_try()

[markj]

Summary

The socket is unused, and not passing it means that there's less to
think about when considering how KTLS is synchronized with the rest of
the socket code. No functional change intended.

[gallatin]

I was concerned at first about isal, but then I remembered that @jhb had moved it from plugging in at the ktls layer to plugging in at the ocf layer