Pull iomap fixlet from Andreas Gruenbacher:
 "Fix buffered write page prefaulting.

  I forgot to send it the previous merge window. I've only improved the
  patch description since"

* tag 'write-page-prefaulting' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  fs/iomap: Fix buffered write page prefaulting