ide: sanitize ide_build_sglist() and ide_destroy_dmatable()

* Move ide_map_sg() calls out from ide_build_sglist()
  to ide_dma_prepare().

* Pass command to ide_destroy_dmatable().

* Rename ide_build_sglist() to ide_dma_map_sg()
  and ide_destroy_dmatable() to ide_dma_unmap_sg().

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/include/linux/ide.h b/include/linux/ide.h
index b350667..03c5209 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1445,8 +1445,7 @@
 void ide_release_dma_engine(ide_hwif_t *);
 
 int ide_dma_prepare(ide_drive_t *, struct ide_cmd *);
-
-void ide_destroy_dmatable(ide_drive_t *);
+void ide_dma_unmap_sg(ide_drive_t *, struct ide_cmd *);
 
 #ifdef CONFIG_BLK_DEV_IDEDMA_SFF
 int config_drive_for_dma(ide_drive_t *);
@@ -1481,7 +1480,8 @@
 static inline void ide_release_dma_engine(ide_hwif_t *hwif) { ; }
 static inline int ide_dma_prepare(ide_drive_t *drive,
 				  struct ide_cmd *cmd) { return 1; }
-static inline void ide_destroy_dmatable(ide_drive_t *drive) { ; }
+static inline void ide_dma_unmap_sg(ide_drive_t *drive,
+				    struct ide_cmd *cmd) { ; }
 #endif /* CONFIG_BLK_DEV_IDEDMA */
 
 #ifdef CONFIG_BLK_DEV_IDEACPI