Remove OpenSSL compat code that misuses the API

Remove OpenSSL compat code that misuses the API

Immediately after EVP_CIPHER_CTX_new() neither EVP_CIPHER_CTX_init()
nor EVP_CIHPER_CTX_reset() should be called: the purpose of the init
function is to initialize a context on the stack while reset clears
a used context for reuse. Neither situation is the case here.

Removing the code also fixes a potential NULL dereference because an
error of reset is not signaled to the caller. Fortunately reset doesn't
currently fail in this situation in current OpenSSL and LibreSSL.