MSI: Consolidate precondition checks

Consolidate precondition checks into a single if statement.

Signed-off-by: Michael Ellerman <[e-mail]>
Acked-by: Eric W. Biederman <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/pci/msi.c

···
 	struct msi_desc *entry;
 	int default_irq;
 
-	if (!pci_msi_enable)
-		return;
-	if (!dev)
-		return;
-
-	if (!dev->msi_enabled)
+	if (!pci_msi_enable || !dev || !dev->msi_enabled)
 		return;
 
 	msi_set_enable(dev, 0);
···
 
 void pci_disable_msix(struct pci_dev* dev)
 {
-	if (!pci_msi_enable)
-		return;
-	if (!dev)
-		return;
-
-	if (!dev->msix_enabled)
+	if (!pci_msi_enable || !dev || !dev->msix_enabled)
 		return;
 
 	msix_set_enable(dev, 0);