Fixes CVE-2016-{9602,9603} and CVE-2017-{2615,2620,2630,5667,5931}. * gnu/packages/qemu.scm (qemu): Update to 2.8.1. * gnu/packages/patches/qemu-CVE-2017-2615.patch, gnu/packages/patches/qemu-CVE-2017-2620.patch, gnu/packages/patches/qemu-CVE-2017-2630.patch, gnu/packages/patches/qemu-CVE-2017-5667.patch, gnu/packages/patches/qemu-CVE-2017-5931.patch: Delete files. * gnu/local.mk (dist_patch_DATA): Remove them.