x86/PCI: Remove unnecessary list_empty(&pci_root_infos) check

list_for_each_entry() handles empty lists, so there's no need to check
whether the list is empty first.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/x86/pci/bus_numa.c

@@ -10,9 +10,6 @@ static struct pci_root_info *x86_find_pci_root_info(int bus)
 {
 	struct pci_root_info *info;
 
-	if (list_empty(&pci_root_infos))
-		return NULL;
-
 	list_for_each_entry(info, &pci_root_infos, list)
 		if (info->busn.start == bus)
 			return info;