container/init: close initial process files on termination

This closes them during the adopt wait delay. This also keeps them alive.

Signed-off-by: Ophestra <cat@gensokyo.uk>

container/fhs/abs.go

@@ -1,7 +1,7 @@
 package fhs
 
 import (
-	_ "unsafe"
+	_ "unsafe" // for go:linkname
 
 	"hakurei.app/container/check"
 )