PCI: Fix typos and whitespace errors

Fix typos in drivers/pci.  Comment and whitespace changes only.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>