pkcs12: check for zero length digest to avoid division by zero

Fixes #16331

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/16332)

providers/implementations/kdfs/pkcs12kdf.c

@@ -64,7 +64,7 @@ static int pkcs12kdf_derive(const unsigned char *pass, size_t passlen,
     }
     vi = EVP_MD_get_block_size(md_type);
     ui = EVP_MD_get_size(md_type);
-    if (ui < 0 || vi <= 0) {
+    if (ui <= 0 || vi <= 0) {
         ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST_SIZE);
         goto end;
     }