Revert "ACPI / scan: do not match drivers against objects having scan handlers"

Commit 9f29ab11 ("ACPI / scan: do not match drivers against objects
having scan handlers") introduced a boot regression on Tony's ia64 HP
rx2600.  Tony says:

  "It panics with the message:

   Kernel panic - not syncing: Unable to find SBA IOMMU: Try a generic or DIG kernel

   [...] my problem comes from arch/ia64/hp/common/sba_iommu.c
   where the code in sba_init() says:

        acpi_bus_register_driver(&acpi_sba_ioc_driver);
        if (!ioc_list) {

   but because of this change we never managed to call ioc_init()
   so ioc_list doesn't get set up, and we die."

Revert it to avoid this breakage and we'll fix the problem it attempted
to address later.
Reported-by: Tony Luck <tony.luck@gmail.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/acpi/scan.c

@@ -740,10 +740,6 @@ static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 
-	/* Skip ACPI device objects with scan handlers attached. */
-	if (acpi_dev->handler)
-		return 0;
-
 	return acpi_dev->flags.match_driver
 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 }