ide: fix ->init_chipset method to return 'int' value

* Return 0 instead of dev->irq in ->init_chipset implementations.

* Fix ->init_chipset method to return 'int' value instead of
  'unsigned int' one.

This fixes ->init_chipset handling for host drivers (cs5530, hpt366
and pdc202xx_new) for which it is possible for this method to fail.

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

drivers/ide/alim15x3.c

@@ -212,7 +212,7 @@ static int ali15x3_dma_setup(ide_drive_t *drive)
  *	appropriate also sets up the 1533 southbridge.
  */
 
-static unsigned int init_chipset_ali15x3(struct pci_dev *dev)
+static int init_chipset_ali15x3(struct pci_dev *dev)
 {
 	unsigned long flags;
 	u8 tmpbyte;