xfs: use struct iomap based DAX PMD fault path

Switch xfs_filemap_pmd_fault() from using dax_pmd_fault() to the new and
improved dax_iomap_pmd_fault().  Also, now that it has no more users,
remove xfs_get_blocks_dax_fault().

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index e7f35d54..ca2ab73 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1711,7 +1711,7 @@ xfs_filemap_pmd_fault(
 	}
 
 	xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
-	ret = dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault);
+	ret = dax_iomap_pmd_fault(vma, addr, pmd, flags, &xfs_iomap_ops);
 	xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
 
 	if (flags & FAULT_FLAG_WRITE)