ide: call ide_build_sglist() prior to ->dma_setup (v2)

* Re-map sg table if needed in ide_build_sglist().

* Move ide_build_sglist() call from ->dma_setup to its users.

* Un-export ide_build_sglist().

v2:
* Build fix for CONFIG_BLK_DEV_IDEDMA=n (noticed by Randy Dunlap).

There should be no functional changes caused by this patch.

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/sgiioc4.c b/drivers/ide/sgiioc4.c
index 1cffe70..ab9433a 100644
--- a/drivers/ide/sgiioc4.c
+++ b/drivers/ide/sgiioc4.c
@@ -429,15 +429,9 @@
 {
 	ide_hwif_t *hwif = drive->hwif;
 	unsigned int *table = hwif->dmatable_cpu;
-	unsigned int count = 0, i = 1;
-	struct scatterlist *sg;
+	unsigned int count = 0, i = hwif->sg_nents;
+	struct scatterlist *sg = hwif->sg_table;
 
-	hwif->sg_nents = i = ide_build_sglist(drive, rq);
-
-	if (!i)
-		return 0;	/* sglist of length Zero */
-
-	sg = hwif->sg_table;
 	while (i && sg_dma_len(sg)) {
 		dma_addr_t cur_addr;
 		int cur_len;