Remove defers from gofer.contextFile
Remove defers from gofer.contextFile

Most are single line methods in hot paths.

PiperOrigin-RevId: 247050267
Change-Id: I428d78723fe00b57483185899dc8fa9e1f01e2ea

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor