Ensure that MDs created via EVP_MD_meth_new() go down the legacy route

MDs created via EVP_MD_meth_new() are inherently legacy and therefore
need to go down the legacy route when they are used.

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/17255)

crypto/evp/digest.c

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index 322cfe7..5fe80a6 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -208,7 +208,8 @@
             || tmpimpl != NULL
 # endif
 #endif
-            || (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) != 0) {
+            || (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) != 0
+            || type->origin == EVP_ORIG_METH) {
         if (ctx->digest == ctx->fetched_digest)
             ctx->digest = NULL;
         EVP_MD_free(ctx->fetched_digest);