Make LVM over AoE work

If the rootfs is on a LVM over AoE, some additional magic is needed.
Possibly this has been broken since ever.

debian/usr/share/initramfs-tools/scripts/local-top/aoe

@@ -29,8 +29,9 @@ configure_networking
 wait_for_udev 10
 
 modprobe aoe
+[ -x /usr/sbin/aoe-discover ] && aoe-discover
 
 # Wait until aoe device files have been generated.
 wait_for_udev 10
 
-[ -x /usr/sbin/aoe-discover ] && aoe-discover
+[ -x /usr/sbin/vgchange ] && vgchange -a y