Backport #19537
There is a potential rare race possible whereby the c.running channel could
be closed twice. Looking at the code I do not see a need for this c.running
channel and therefore I think we can remove this. (I think the c.running
might have been some attempt to prevent a hang but the use of os.Pipes should
prevent that.)
Signed-off-by: Andrew Thornton <art27@cantab.net>