revert bad fix

partially revert my commit 34cabe837dbb78 "loplugin:unreffun"

Change-Id: Idbfc9d1e43180c7c14e58c7b9417f3001d9805d4
Revert "loplugin:unreffun"

This reverts commit e3246e806cad5f9d2c05c3408adc3019da5a575d.
Which was a mistake.