Restore qemu-kvm install for CentOS

The kvmibm removal I009ae4779588615633bff81d0c47a1b879ec9279
incorrectly removed this (the check was install if *not* kvmibm).
Since we don't support kvmibm any more, it should be safe to install
everywhere as done here.

For the full history, it started with us installing qemu-kvm-ev with
Ide91b261f35fb19d8bd7155ca016fa3b76a45ea1, then we fixed it to be more
generic and just install qemu-kvm with
I46da627c0da8925064862fdc283db81591979285, then Fedora 26 support in
I5c79ad1ef0b11dba30c931a59786f9eb7e7f8587 made this install everywhere
*but* kvmibm.

Change-Id: If3e9661451ad1055e7c8d670605a53095f0aeda4
diff --git a/lib/nova_plugins/functions-libvirt b/lib/nova_plugins/functions-libvirt
index c852738..dbfa3b5 100644
--- a/lib/nova_plugins/functions-libvirt
+++ b/lib/nova_plugins/functions-libvirt
@@ -72,6 +72,13 @@
         pip_install_gr libvirt-python
         #pip_install_gr <there-si-no-guestfs-in-pypi>
     elif is_fedora || is_suse; then
+
+        # Note that in CentOS/RHEL this needs to come from the RDO
+        # repositories (qemu-kvm-ev ... which provides this package)
+        # as the base system version is too old.  We should have
+        # pre-installed these
+        install_package qemu-kvm
+
         install_package libvirt libvirt-devel
         pip_uninstall libvirt-python
         pip_install_gr libvirt-python