WaE: overriding virtual function declaration not marked 'override'

Change-Id: Ieb8da224e02a9c8e19eabb4c5bcbd81120900245
WaE: unused variable 'aOSRelease'

Actually we don't need the aOS variable either, we can check maOS directly.

Change-Id: Ib14d6baf0bda28a45361886059629460641571bc
WaE: work around loplugin:unreffun and loplugin:externandnotdefined

Change-Id: I5192ad1f068746da257f3e1d9340325956b1e69d