reformat with indent -linux

Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: dqminh)
define PR_SET_CHILD_SUBREAPER if not set

Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: dqminh)
Merge pull request #300 from dqminh/subreaper

define PR_SET_CHILD_SUBREAPER if not set