Revert "fb_defio: fix for non-dirty ptes"

Revert "fb_defio: fix for non-dirty ptes"

This reverts commit 065b2fe1f538d5bc484a46ae1628cca00b97bcd3 ("fb_defio:
fix for non-dirty ptes").

Although the fix provided is correct, it's been suggested to avoid the
underlying race in the same way as it is currently done in filesystems
like NFS, for maintainability.

A following patch "fb_defio: redo fix for non-dirty ptes" will provide
such an alternate fix.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>