* gnu/packages/patches/qemu-CVE-2015-5745.patch: New file.
* gnu/packages/patches/qemu-CVE-2015-3456.patch,
gnu/packages/patches/qemu-CVE-2015-5154-pt1.patch,
gnu/packages/patches/qemu-CVE-2015-5154-pt2.patch,
gnu/packages/patches/qemu-CVE-2015-5154-pt3.patch,
gnu/packages/patches/qemu-CVE-2015-5158.patch: Delete files.
* gnu-system.am (dist_patch_DATA): Add new file and remove the deleted ones.
* gnu/packages/qemu.scm (qemu): Update to 2.3.1. Add new patch and remove the
deleted ones.