more crypto test fix

Change-Id: I7fc3952cefad6f76a8e021a7a23e99a83a3cde16
diff --git a/tests/unit-tests/crypto-helper.t.cpp b/tests/unit-tests/crypto-helper.t.cpp
index e157711..f425f64 100644
--- a/tests/unit-tests/crypto-helper.t.cpp
+++ b/tests/unit-tests/crypto-helper.t.cpp
@@ -212,7 +212,7 @@
   BOOST_CHECK_EQUAL_COLLECTIONS(tag, tag + 16, expected_tag, expected_tag + sizeof(expected_tag));
 
   uint8_t decrypted[256] = {0};
-  size = aes_gcm_128_decrypt(ciphertext, size, nullptr, 0, tag, key, iv, decrypted);
+  size = aes_gcm_128_decrypt(ciphertext, size, empty_buffer, 0, tag, key, iv, decrypted);
   BOOST_CHECK(size == 0);
 }