inspection: Better checking for Windows root disks (RHBZ#729075).

inspection: Better checking for Windows root disks (RHBZ#729075).

Previously any disk that had /autoexec.bat or /boot.ini or /ntldr
would be picked up as a candidate for a Windows root disk.  If further
checking could not find any systemroot (eg. /windows) then this would
result in complete failure of inspection.

In particular, this got confused by Hp_recovery partitions which have
/autoexec.bat, but don't have a systemroot in one of the usual places
(they have /MiniNT instead).

What we do now is to properly investigate all possible systemroot
places before deciding this is a Windows systemroot, so the subsequent
failure cannot occur.

(Thanks to lorimar for reporting this bug).
(cherry picked from commit 2c57305f72cd6181d1849ae6e1b892aa01c7f844)