iomap: remove the iomap arguments to ->page_{prepare,done}

iomap: remove the iomap arguments to ->page_{prepare,done}

These aren't actually used by the only instance implementing the methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>