[PATCH v4] lib/scatterlist: use page iterator in the mapping iterator

For better code reuse use the newly added page iterator to iterate through the pages. The offset, length within the page is still calculated by the mapping iterator as well as the actual mapping. Idea from Tejun Heo. v1-v3: - original version v4: - The dw_mmc driver used sg_mapping_iter::__sg,

[PATCH v4] lib/scatterlist: use page iterator in the mapping iterator

For better code reuse use the newly added page iterator to iterate through the pages. The offset, length within the page is still calculated by the mapping iterator as well as the actual mapping. Idea from Tejun Heo. v1-v3: - original version v4: - The dw_mmc driver used sg_mapping_iter::__sg,