main/xen: use default screendir location

ref #1181

Otherwise screen -x will not work without manually setting screen dir
(cherry picked from commit 01f58adb)

main/xen/APKBUILD

@@ -3,7 +3,7 @@
 # Maintainer: William Pitcock <nenolod@dereferenced.org>
 pkgname=xen
 pkgver=4.1.2
-pkgrel=11
+pkgrel=12
 pkgdesc="Xen hypervisor"
 url="http://www.xen.org/"
 arch="x86 x86_64"
@@ -137,6 +137,6 @@ ed262f15fb880badb53575539468646c  xenconsoled.initd
 ec2252c72050d7d5870a3a629b873ba6  xenconsoled.confd
 89c936ddf327a3a78eaee33835880517  xend.initd
 9261ad0f285836c1b0ea07f306e4586e  xend.confd
-9cc0883d472987038fd464a7e28372e3  xendomains.initd
-f3162b7c261bcaf49a67bd41d987df84  xendomains.confd
+35448ff063f8123ec4bba2e001f39c6c  xendomains.initd
+9b20e056d475b50586cf9e1fc94e13c4  xendomains.confd
 9df68ac65dc3f372f5d61183abdc83ff  xen-consoles.logrotate"

main/xen/xendomains.confd

@@ -23,3 +23,8 @@ SCREEN_NAME="xen"
 # in the event of a crash.
 
 SCREEN_LOG_INTERVAL="1"
+
+# The location where screen stores the connection sockets
+
+SCREENDIR=/tmp/screens/S-root
+

main/xen/xendomains.initd

@@ -29,7 +29,7 @@ using_screen() {
 }
 
 set_screen_cmd() {
-	export SCREENDIR=/var/run/xen-screens
+	export SCREENDIR=${SCREENDIR:-/tmp/screens/S-root}
 	checkpath --directory --mode 700 "$SCREENDIR"
 	screen_cmd="screen -c ${SCREENRC:-/dev/null} -q -r ${SCREEN_NAME:=xen} -X"
 }