Merge pull request #1763 from aaronjense/ecc-check-key-type

Fix error with wolfCrypt-JNI having ECC_PRIVATEKEY_ONLY and d != NULL

wolfcrypt/src/ecc.c

@@ -6428,7 +6428,8 @@ int wc_ecc_export_ex(ecc_key* key, byte* qx, word32* qxLen,
 
     /* private key, d */
     if (d != NULL) {
-        if (dLen == NULL || key->type != ECC_PRIVATEKEY)
+        if (dLen == NULL || 
+            (key->type != ECC_PRIVATEKEY && key->type != ECC_PRIVATEKEY_ONLY))
             return BAD_FUNC_ARG;
 
     #ifdef WOLFSSL_ATECC508A