* gnu/packages/qemu.scm (qemu)[source]: Add patches. * gnu/packages/patches/qemu-CVE-2017-2615, gnu/packages/patches/qemu-CVE-2017-5578, gnu/packages/patches/qemu-CVE-2017-5579, gnu/packages/patches/qemu-CVE-2017-5856: New files. * gnu/local.mk (dist_patch_DATA): Register them.