PCI: Allocate dma_alias_mask with bitmap_zalloc()

Switch to bitmap_zalloc() to show clearly what we are allocating.  Besides
that it returns pointer of bitmap type ("unsigned long *") instead of the
opaque "void *".

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.c

@@ -5690,8 +5690,7 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
 void pci_add_dma_alias(struct pci_dev *dev, u8 devfn)
 {
 	if (!dev->dma_alias_mask)
-		dev->dma_alias_mask = kcalloc(BITS_TO_LONGS(U8_MAX),
-					      sizeof(long), GFP_KERNEL);
+		dev->dma_alias_mask = bitmap_zalloc(U8_MAX, GFP_KERNEL);
 	if (!dev->dma_alias_mask) {
 		pci_warn(dev, "Unable to allocate DMA alias mask\n");
 		return;

drivers/pci/probe.c

@@ -2143,7 +2143,7 @@ static void pci_release_dev(struct device *dev)
 	pcibios_release_device(pci_dev);
 	pci_bus_put(pci_dev->bus);
 	kfree(pci_dev->driver_override);
-	kfree(pci_dev->dma_alias_mask);
+	bitmap_free(pci_dev->dma_alias_mask);
 	kfree(pci_dev);
 }