Remove session_ctx macro.

Don't pollute the embedder's namespace with a session_ctx macro. It looks like
the difference was that, without TLS extensions, session_ctx was ctx rather
than initial_ctx. Now it's always initial_ctx. Retain the semantics of
switching SSL_CTX's out after the fact, until/unless we decide to replace that
with something less scary-sounding.

Change-Id: Ie5df5138aec25218ca80031cf645671968b8a54a
Reviewed-on: https://boringssl-review.googlesource.com/1663
Reviewed-by: Adam Langley <agl@google.com>
3 files changed