ide: make ide_hwif_t.ide_dma_{host_off,off_quietly} void (v2)

* since ide_hwif_t.ide_dma_{host_off,off_quietly} always return '0'
  make these functions void and while at it drop "ide_" prefix
* fix comment for __ide_dma_off_quietly()
* make __ide_dma_{host_off,off_quietly,off}() void and drop "__" prefix

v2:
* while at it rename atiixp_ide_dma_host_off() to atiixp_dma_host_off(),
  sgiioc4_ide_dma_{host_off,off_quietly}() to sgiioc4_dma_{host_off,off_quietly}()
  and sl82c105_ide_dma_off_quietly() to sl82c105_dma_off_quietly()
  [ Noticed by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 09c30cb..5ecdb11 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -753,7 +753,7 @@
 
 #ifdef CONFIG_BLK_DEV_IDEDMA
 	if (hwif->ide_dma_check)	 /* check if host supports DMA */
-		hwif->ide_dma_host_off(drive);
+		hwif->dma_host_off(drive);
 #endif
 
 	/*
@@ -832,7 +832,7 @@
 	if (speed >= XFER_SW_DMA_0)
 		hwif->ide_dma_host_on(drive);
 	else if (hwif->ide_dma_check)	/* check if host supports DMA */
-		hwif->ide_dma_off_quietly(drive);
+		hwif->dma_off_quietly(drive);
 #endif
 
 	switch(speed) {
@@ -1042,12 +1042,12 @@
 {
 #ifdef CONFIG_BLK_DEV_IDEDMA
 	if (drive->crc_count) {
-		(void) HWIF(drive)->ide_dma_off_quietly(drive);
+		drive->hwif->dma_off_quietly(drive);
 		ide_set_xfer_rate(drive, ide_auto_reduce_xfer(drive));
 		if (drive->current_speed >= XFER_SW_DMA_0)
 			(void) HWIF(drive)->ide_dma_on(drive);
 	} else
-		(void)__ide_dma_off(drive);
+		ide_dma_off(drive);
 #endif
 }