use buffered channel so goroutine does not get blocked on done <- true when a timeout occurs.

Docker-DCO-1.1-Signed-off-by: Anandkumar Patel <anandkumarpatel@gmail.com> (github: anandkumarpatel)
Merge pull request #5955 from anandkumarpatel/5923-fix-leaking-go-routine

5923-fix-leaking-go-routine