veyron/services/mgmt/device/deviced: flush log after printing token
veyron/services/mgmt/device/deviced: flush log after printing token

Change-Id: Id8f7c861da1ee0b1c800ca1a81426cc318db8c6d

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref