Fix incorrect return check of BN_bn2nativepad

Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NPaul Dale <pauli@openssl.org>
Reviewed-by: NTomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16943)

crypto/evp/ctrl_params_translate.c

@@ -465,8 +465,8 @@ static int default_fixup_args(enum state state,
                         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
                         return 0;
                     }
-                    if (!BN_bn2nativepad(ctx->p2,
-                                         ctx->allocated_buf, ctx->buflen)) {
+                    if (BN_bn2nativepad(ctx->p2,
+                                         ctx->allocated_buf, ctx->buflen) < 0) {
                         OPENSSL_free(ctx->allocated_buf);
                         ctx->allocated_buf = NULL;
                         return 0;

test/keymgmt_internal_test.c

@@ -88,7 +88,7 @@ static int get_ulong_via_BN(const OSSL_PARAM *p, unsigned long *goal)
     int ret = 1;                 /* Ever so hopeful */
 
     if (!TEST_true(OSSL_PARAM_get_BN(p, &n))
-        || !TEST_true(BN_bn2nativepad(n, (unsigned char *)goal, sizeof(*goal))))
+        || !TEST_int_ge(BN_bn2nativepad(n, (unsigned char *)goal, sizeof(*goal)), 0))
         ret = 0;
     BN_free(n);
     return ret;