This patch makes the signature of the _cleanup() functions consistent
among the SSL backends, in preparation for unifying the way all SSL
backends are accessed.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Carrying on from commit 037cd0d991, removed the following unimplemented
instances of curlssl_close_all():
Curl_axtls_close_all()
Curl_darwinssl_close_all()
Curl_cyassl_close_all()
Curl_gskit_close_all()
Curl_gtls_close_all()
Curl_nss_close_all()
Curl_polarssl_close_all()
Prefer void for unused parameters, rather than assigning an argument to
itself as a) unintelligent compilers won't optimize it out, b) it can't
be used for const parameters, c) it will cause compilation warnings for
clang with -Wself-assign and d) is inconsistent with other areas of the
curl source code.
