Don't ignore error from umount
Don't ignore error from umount

The previous behavior was to return any errors from umount in the
SetupConfigDrive method, but to ignore errors from fuser.

[#181644134] Update bosh-agent linter to use golangci-lint instead

Signed-off-by: Aram Price <ebc3d4dc278319bab47ffb2bc55fc82b40fcbaf7@vmware.com>

cloudfoundry/bosh-agent,cloudfoundry/bosh-agent