Look for device.map in any directory beneath /boot. (This is required
to find device.map in /boot/grub2 in addition to /boot/grub.)

Index: augeas-1.1.0/lenses/device_map.aug
===================================================================
--- augeas-1.1.0.orig/lenses/device_map.aug
+++ augeas-1.1.0/lenses/device_map.aug
@@ -21,7 +21,7 @@ module Device_map =
 
   let lns = ( empty | comment | map ) *
 
-  let xfm = transform lns (incl "/boot/grub/device.map")
+  let xfm = transform lns (incl "/boot/*/device.map")
 
 (* Local Variables: *)
 (* mode: caml *)