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

tv42/old-go,pombredanne/go-deleteme,apparentlymart/golang,gnanderson/go,tv42/old-go,tv42/old-go,gnanderson/go,dsriram/golang,dsriram/golang,apparentlymart/golang,tv42/old-go,pombredanne/go-deleteme,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,dsriram/golang,apparentlymart/golang,apparentlymart/golang,gnanderson/go,gnanderson/go,pombredanne/go-deleteme,gnanderson/go,tv42/old-go,dsriram/golang,tv42/old-go,apparentlymart/golang,tv42/old-go,gnanderson/go,apparentlymart/golang,pombredanne/go-deleteme,gnanderson/go,apparentlymart/golang,pombredanne/go-deleteme