lib/nova: make redirects happen in correct order

It should redirect stdout to /dev/null firstly,
then redirect stderr to whatever stdout currently points at.

Change-Id: I4666fa90a96301f0b504a8501f0ffc3fe17616b0
diff --git a/lib/nova b/lib/nova
index 6441a89..6348950 100644
--- a/lib/nova
+++ b/lib/nova
@@ -332,7 +332,7 @@
                 if [ ! -e /dev/kvm ]; then
                     echo "WARNING: Switching to QEMU"
                     LIBVIRT_TYPE=qemu
-                    if which selinuxenabled 2>&1 > /dev/null && selinuxenabled; then
+                    if which selinuxenabled >/dev/null 2>&1 && selinuxenabled; then
                         # https://bugzilla.redhat.com/show_bug.cgi?id=753589
                         sudo setsebool virt_use_execmem on
                     fi