openssl binary with OPENSSL_BIN.  This will allow us to use the OPENSSL
variable from mk.conf or the make(1) command line indicating if we're
building with our without OpenSSL, and ultimately get the regress tests
working in the OPENSSL=no configuration.

OpenBSD-Regress-ID: 2d788fade3264d7803e5b54cae8875963f688c4e