From: Arun Sharma <arun.sharma@intel.com>

Based on some earlier discussion:

http://marc.theaimsgroup.com/?t=106015010700002&r=1&w=2

here's a new patch that attempts to disable BLK_DEV_FD on platforms which
don't support it.  The patch also attempts to remove the duplication of the
logic in compat_ioctl.h.