net: fix flaky test The test failed on one of the builders with: timeout_test.go:594: 	ln.Accept: accept tcp 127.0.0.1:19373: use of closed network connection http://build.golang.org/log/e83f4a152b37071b9d079096e15913811ad296b5
net: fix flaky test
The test failed on one of the builders with:
timeout_test.go:594: 	ln.Accept: accept tcp 127.0.0.1:19373: use of closed network connection
http://build.golang.org/log/e83f4a152b37071b9d079096e15913811ad296b5

R=golang-dev, bradfitz, dave, mikioh.mikioh, remyoudompheng, rsc
CC=golang-dev
http://codereview.appspot.com/6859043

glycerine/jeaten-go-arrayof-structof,d0f/go-zh,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,rdp/rogerpack2005-golang,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,bryanxu/go-zh,scirelli/scirelli-go,rdp/rogerpack2005-golang,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,d0f/go-zh,rdp/rogerpack2005-golang,bryanxu/go-zh,scirelli/scirelli-go,mhennings/marcohennings-go,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,scirelli/scirelli-go,bryanxu/go-zh,bryanxu/go-zh,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,sanjosh/sanjos100-tipc,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,bryanxu/go-zh,bryanxu/go-zh,rdp/rogerpack2005-golang,d0f/go-zh,webfd/go-zh,rdp/rogerpack2005-golang,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,d0f/go-zh,webfd/go-zh,d0f/go-zh,bryanxu/go-zh,d0f/go-zh,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,webfd/go-zh,d0f/go-zh,webfd/go-zh,scirelli/scirelli-go,mhennings/marcohennings-go,mhennings/marcohennings-go,mhennings/marcohennings-go,bryanxu/go-zh,scirelli/scirelli-go,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,scirelli/scirelli-go,webfd/go-zh,rflanagan/reginaldflanagan-project1,rflanagan/reginaldflanagan-project1,scirelli/scirelli-go,mhennings/marcohennings-go,webfd/go-zh,rdp/rogerpack2005-golang,rflanagan/reginaldflanagan-project1