ACPI / PCI: fix acpi_pci_irq_enable() memory leak

In acpi_pci_irq_enable(), 'entry' is allocated by kzalloc() in
acpi_pci_irq_check_entry() (invoked from acpi_pci_irq_lookup()). However,
it is not deallocated if acpi_pci_irq_valid() returns false, leading to a
memory leak. To fix this issue, free 'entry' before returning 0.

Fixes: e237a551 ("x86/ACPI/PCI: Recognize that Interrupt Line 255 means "not connected"")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/pci_irq.c

@@ -449,8 +449,10 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
 		 * No IRQ known to the ACPI subsystem - maybe the BIOS /
 		 * driver reported one, then use it. Exit in any case.
 		 */
-		if (!acpi_pci_irq_valid(dev, pin))
+		if (!acpi_pci_irq_valid(dev, pin)) {
+			kfree(entry);
 			return 0;
+		}
 
 		if (acpi_isa_register_gsi(dev))
 			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",