secur32: Use empty credentials when cached creds fail.

dlls/secur32/ntlm.c

@@ -659,8 +659,7 @@ static SECURITY_STATUS SEC_ENTRY ntlm_InitializeSecurityContextW(
             if(!strncmp(buffer, "PW", 2))
             {
                 TRACE("Using cached credentials failed.\n");
-                ret = SEC_E_NO_CREDENTIALS;
-                goto isc_end;
+                lstrcpynA(buffer, "PW AA==", max_len-1);
             }
             else /* Just do a noop on the next run */
                 lstrcpynA(buffer, "OK", max_len-1);

dlls/secur32/tests/ntlm.c

@@ -1309,7 +1309,6 @@ static void test_null_auth_data(void)
     status = pInitializeSecurityContextA(&cred, NULL, (SEC_CHAR *)user,
                                          ISC_REQ_CONNECTION, 0, SECURITY_NETWORK_DREP,
                                          NULL, 0, &ctx, &buffer_desc, &attr, &ttl);
-    todo_wine
     ok(status == SEC_I_CONTINUE_NEEDED, "InitializeSecurityContextA failed %s\n", getSecError(status));
 }