go.talks/pkg/socket: don't log EOF error; this is always benign
go.talks/pkg/socket: don't log EOF error; this is always benign

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7308043

bryanxu/go-zh.talks,d0f/go-zh.talks,bryanxu/go-zh.talks,d0f/go-zh.talks,webfd/go-zh.talks,d0f/go-zh.talks,d0f/go-zh.talks,bryanxu/go-zh.talks,bryanxu/go-zh.talks,bryanxu/go-zh.talks,bryanxu/go-zh.talks,webfd/go-zh.talks,webfd/go-zh.talks,webfd/go-zh.talks,webfd/go-zh.talks,webfd/go-zh.talks,d0f/go-zh.talks,d0f/go-zh.talks