Make grub-probe work with symbolic links under /dev/mapper as well

as with real block devices.  The Linux world seems to be (at best)
in transition here, and GRUB shouldn't get caught in the middle.
* kern/emu/getroot.c (find_root_device): Follow symbolic links under
/dev/mapper.

diff --cc ChangeLog
index a8e3e5284c91e0d2765ed6305aa5911b3c4d7209,a8e3e5284c91e0d2765ed6305aa5911b3c4d7209..9658486698b41a3da75e1f4c57fc26e70a7d5224
--- 1/ChangeLog
--- 2/ChangeLog
+++ b/ChangeLog
@@@ -1,3 -1,3 +1,12 @@@
++2010-05-28  Colin Watson  <cjwatson@ubuntu.com>
++
++      Make grub-probe work with symbolic links under /dev/mapper as well
++      as with real block devices.  The Linux world seems to be (at best)
++      in transition here, and GRUB shouldn't get caught in the middle.
++
++      * kern/emu/getroot.c (find_root_device): Follow symbolic links under
++      /dev/mapper.
++
  2010-05-27  Colin Watson  <cjwatson@ubuntu.com>
  
        * util/grub-script-check.c (main): Ensure defined behaviour on empty