hpt366: switch to using pci_get_slot

Switch to using pci_get_slot() to get to the function 1 of HPT36x/374 chips --
there's no need for the driver itself to walk the list of the PCI devices, and
it also forgets to check the bus number of the device found.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>