PCI: clean up search.c a lot

This cleans up the search.c file, now using the pci list of devices that
are created for the driver core, instead of relying on our separate list
of devices.  It's better to use the functions already created for this
kind of thing, instead of rolling our own all the time.

This work is done in anticipation of getting rid of that second list of
pci devices all together.

And it ends up saving code, always a nice benefit.

This also removes one compiler warning for when CONFIG_PCI_LEGACY is
enabled as we no longer internally use the deprecated functions anymore.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/pci.h

@@ -519,7 +519,7 @@ struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
 				struct pci_dev *from);
 struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
 				unsigned int ss_vendor, unsigned int ss_device,
-				struct pci_dev *from);
+				const struct pci_dev *from);
 struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn);
 struct pci_dev *pci_get_bus_and_slot(unsigned int bus, unsigned int devfn);
 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
@@ -792,7 +792,7 @@ static inline struct pci_dev *pci_get_subsys(unsigned int vendor,
 					     unsigned int device,
 					     unsigned int ss_vendor,
 					     unsigned int ss_device,
-					     struct pci_dev *from)
+					     const struct pci_dev *from)
 {
 	return NULL;
 }