ide: check drive->present in ide_get_paired_drive()

* Change ide_get_paired_drive() to return NULL if peer device
  is not present and update all users accordingly.

While at it:

* ide_get_paired_drive() -> ide_get_pair_dev()

* Use ide_get_pair_dev() in cs5530.c, sc1200.c and via82cxxx.c.

There should be no functional changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/arm/palm_bk3710.c b/drivers/ide/arm/palm_bk3710.c
index 6cea984..320971c 100644
--- a/drivers/ide/arm/palm_bk3710.c
+++ b/drivers/ide/arm/palm_bk3710.c
@@ -180,7 +180,7 @@
 	val32 |= (t2i << (dev ? 8 : 0));
 	writel(val32, base + BK3710_DATRCVR);
 
-	if (mate && mate->present) {
+	if (mate) {
 		u8 mode2 = ide_get_best_pio_mode(mate, 255, 4);
 
 		if (mode2 < mode)
@@ -230,7 +230,7 @@
 	 * Obtain the drive PIO data for tuning the Palm Chip registers
 	 */
 	cycle_time = ide_pio_cycle_time(drive, pio);
-	mate = ide_get_paired_drive(drive);
+	mate = ide_get_pair_dev(drive);
 	palm_bk3710_setpiomode(base, mate, is_slave, cycle_time, pio);
 }