PCI/MSI: Make msix_update_entries() smarter

No need to walk the descriptors and check for each one whether the entries
pointer function argument is NULL. Do it once.

Signed-off-by: Thomas Gleixner <[e-mail]>
Tested-by: Juergen Gross <[e-mail]>
Reviewed-by: Jason Gunthorpe <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Acked-by: Bjorn Helgaas <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/pci/msi.c

···
 {
 	struct msi_desc *entry;
 
-	for_each_pci_msi_entry(entry, dev) {
-		if (entries) {
+	if (entries) {
+		for_each_pci_msi_entry(entry, dev) {
 			entries->vector = entry->irq;
 			entries++;
 		}