flash: Suppress spurious error message.

full payloads don't exist in many normal cases, such as when a test
image is specified. Don't print an error message in this case.

BUG=chromium:1017415
TEST=cros flash --debug  ssh://100.90.29.199 latest

Change-Id: I68a650f049af49e87a8d64d6545cbcd5ed3b8eb5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1929895
Tested-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
diff --git a/cli/flash_unittest.py b/cli/flash_unittest.py
index fb982e8..2798d01 100644
--- a/cli/flash_unittest.py
+++ b/cli/flash_unittest.py
@@ -111,9 +111,9 @@
       # Call to download full_payload and stateful. No other calls.
       mock_xbuddy.assert_has_calls(
           [mock.call('/path/to/image/full_payload', mock.ANY,
-                     static_dir=flash.DEVSERVER_STATIC_DIR),
+                     static_dir=flash.DEVSERVER_STATIC_DIR, silent=True),
            mock.call('/path/to/image/stateful', mock.ANY,
-                     static_dir=flash.DEVSERVER_STATIC_DIR)])
+                     static_dir=flash.DEVSERVER_STATIC_DIR, silent=True)])
       self.assertEqual(mock_xbuddy.call_count, 2)
 
   def testTestImage(self):
@@ -130,7 +130,7 @@
       # Call to download full_payload and image. No other calls.
       mock_xbuddy.assert_has_calls(
           [mock.call('/path/to/image/full_payload', mock.ANY,
-                     static_dir=flash.DEVSERVER_STATIC_DIR),
+                     static_dir=flash.DEVSERVER_STATIC_DIR, silent=True),
            mock.call('/path/to/image', mock.ANY,
                      static_dir=flash.DEVSERVER_STATIC_DIR)])
       self.assertEqual(mock_xbuddy.call_count, 2)