run fork with timeout: only special case timeout error in list context

run fork with timeout: only special case timeout error in list context

run_with_timeout() will treat a timeout error differently when called
in list context and run_fork_with_timeout() should do the same. Ensure
this by calling run_with_timeout() in list context if and only if
run_fork_with_timeout() is called in list context too.

Fixes: a6aa0ae ("run with timeout: return if timeout happened in list context")
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>