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.py b/cli/flash.py
index 4950f42..c61d21a 100644
--- a/cli/flash.py
+++ b/cli/flash.py
@@ -443,13 +443,13 @@
       try:
         translated_path, _ = ds_wrapper.GetImagePathWithXbuddy(
             os.path.join(self.image, 'full_payload'), self.board,
-            static_dir=DEVSERVER_STATIC_DIR)
+            static_dir=DEVSERVER_STATIC_DIR, silent=True)
         payload_dir = os.path.dirname(
             ds_wrapper.TranslatedPathToLocalPath(translated_path,
                                                  DEVSERVER_STATIC_DIR))
         ds_wrapper.GetImagePathWithXbuddy(
             os.path.join(self.image, 'stateful'), self.board,
-            static_dir=DEVSERVER_STATIC_DIR)
+            static_dir=DEVSERVER_STATIC_DIR, silent=True)
         fetch_image = False
       except (ds_wrapper.ImagePathError, ds_wrapper.ArtifactDownloadError):
         logging.info('Could not find full_payload or stateful for "%s"',