Bug#612402: more of the patch

[Daniel Pocock]

This is also needed to correctly generate /boot/grub/grug.cfg with UUID
syntax for btrfs RAID on top of lvm:



--- /etc/grub.d/10_linux.orig	2012-08-29 15:01:29.808976702 +0200
+++ /etc/grub.d/10_linux	2012-08-29 15:06:36.574297444 +0200
@@ -50,7 +50,7 @@

 if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}"
= "xtrue" ] \
     || ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
-    || uses_abstraction "${GRUB_DEVICE}" lvm; then
+    || (uses_abstraction "${GRUB_DEVICE}" lvm && [ ${GRUB_FS} != btrfs
] ); then
   LINUX_ROOT_DEVICE=${GRUB_DEVICE}
 else
   LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}