ide: make probe_hwif() return an error value

Make probe_hwif() return an error value.

While at it:

* Remove comment about MAX_DRIVES == 2 limitation (it is not special to
  probe_hwif(), it is a general assumption taken by a lot of IDE code).

* Rename probe_hwif() to ide_probe_port().

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 495e387..16b1f6e 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -1166,7 +1166,7 @@
 
 /*
  * ide_wait_not_busy() waits for the currently selected device on the hwif
- * to report a non-busy status, see comments in probe_hwif().
+ * to report a non-busy status, see comments in ide_probe_port().
  */
 int ide_wait_not_busy(ide_hwif_t *hwif, unsigned long timeout)
 {