mmc: sdio: improve mmc_io_rw_extended

Improve mmc_io_rw_extended a little:
- using DIV_ROUND_UP achieves the same but is better readable
- simplify code by using sg_set_buf
- simplify one statement by using -= operator

Signed-off-by: Heiner Kallweit <[e-mail]>
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/core/sdio_ops.c

···
 	data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
 
 	left_size = data.blksz * data.blocks;
-	nents = (left_size - 1) / seg_size + 1;
+	nents = DIV_ROUND_UP(left_size, seg_size);
 	if (nents > 1) {
 		if (sg_alloc_table(&sgtable, nents, GFP_KERNEL))
 			return -ENOMEM;
···
 		data.sg_len = nents;
 
 		for_each_sg(data.sg, sg_ptr, data.sg_len, i) {
-			sg_set_page(sg_ptr, virt_to_page(buf + (i * seg_size)),
-					min(seg_size, left_size),
-					offset_in_page(buf + (i * seg_size)));
-			left_size = left_size - seg_size;
+			sg_set_buf(sg_ptr, buf + i * seg_size,
+				   min(seg_size, left_size));
+			left_size -= seg_size;
 		}
 	} else {
 		data.sg = &sg;