devices: vvu-proxy: Reports an error happening in worker thread
devices: vvu-proxy: Reports an error happening in worker thread

BUG=none
TEST=run vvu

Change-Id: I80f05c7c0d066f458279f6908b4ba7296f873e49
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3640878
Reviewed-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Reviewed-by: Abhishek Bhardwaj <4731196bfa2312dffce2e96e4b970d725db87a47@chromium.org>
Auto-Submit: Keiichi Watanabe <815e4e8f7c92a23424d7c3f51ead622bcedbc720@chromium.org>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Commit-Queue: Keiichi Watanabe <815e4e8f7c92a23424d7c3f51ead622bcedbc720@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm