Security update for xen (important)

xen was updated to fix 12 security issues. These security issues were fixed: - CVE-2015-7972: Populate-on-demand balloon size inaccuracy can crash guests bsc951845. - CVE-2015-7969: Leak of main per-domain vcpu pointer array DoS bsc950703. - CVE-2015-7969: Leak of per-domain profiling-related vcp...