Revert "x86: fix pmd_bad and pud_bad to support huge pages"

This reverts commit cded932b

.

Arjan bisected down a boot-time hang to this, saying:
  ".. it prevents the kernel to finish booting on my (Penryn based)
   laptop.  The boot stops right after freeing the init memory."

and while it's not clear exactly what triggers it, at this stage we're
better off just reverting it while Ingo tries to figure out what went
wrong.

Requested-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Nish Aravamudan <nish.aravamudan@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>