* benchmark pallet: Error if files are overwritten twice Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> * Fix Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> * Fix error message Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io> --------- Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>