Merge branch 'vmcore-iov_iter' into features

Pull changes that finalize switching of copy_oldmem_page() callback
to iov_iter interface. These changes were pulled in work.iov_iter of
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>