mkfifo /var/run/screen/S-user/xxxx.pts-yy.hostname failed

if /run/screen/S-user exists, kill -chld recreates the fifo.

if /run/screen/S-user does not exist, kill -chld kills screen. this is not very robust.

if screen can't be bothered to recreate the directory, it could at least have the courtesy to refrain from destroying itself.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: screen 4.2.1-3
ProcVersionSignature: Ubuntu 3.19.0-9.9-generic 3.19.1
Uname: Linux 3.19.0-9-generic i686
ApportVersion: 2.16.2-0ubuntu4
Architecture: i386
Date: Tue Mar 24 09:21:13 2015
InstallationDate: Installed on 2015-01-14 (68 days ago)
InstallationMedia: Lubuntu 14.10 "Utopic Unicorn" - Release i386 (20141022.1)
SourcePackage: screen
UpgradeStatus: No upgrade log present (probably fresh install)