pci: avoid compiler warning in quirks.c

Introduced by commit 5b889bf2 ("PCI: Fix build if quirks are not
enabled"), which made the pci_dev_reset_methods[] array static and
'const', but didn't then change the code to match, and use a const
pointer when moving it to quirks.c.

Trivially fixed by just adding the required 'const' to the iterator
variable.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pci/quirks.c

@@ -2694,7 +2694,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
 
 int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 {
-	struct pci_dev_reset_methods *i;
+	const struct pci_dev_reset_methods *i;
 
 	for (i = pci_dev_reset_methods; i->reset; i++) {
 		if ((i->vendor == dev->vendor ||