Fix EVP_CIPHER_CTX_set_padding for legacy path

Fixes #13057

When using an engine, there is no cipher->prov so a call to
EVP_CIPHER_CTX_set_padding() returns an error when
evp_do_ciph_ctx_setparams() is called. For the legacy path it needs to
avoid doing the call and just return 1.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NBen Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/13437)

crypto/evp/evp_enc.c

@@ -948,6 +948,8 @@ int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
     else
         ctx->flags |= EVP_CIPH_NO_PADDING;
 
+    if (ctx->cipher != NULL && ctx->cipher->prov == NULL)
+        return 1;
     params[0] = OSSL_PARAM_construct_uint(OSSL_CIPHER_PARAM_PADDING, &pd);
     ok = evp_do_ciph_ctx_setparams(ctx->cipher, ctx->provctx, params);