ACPI / hotplug / PCI: Do not clear event callback pointer for docks

After recent changes adding dock station handling to the ACPI hotplug
core, it is not necessary to clear the .event() pointer in the
ACPIPHP device hotplug context for dock stations any more, so don't
do that.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/pci/hotplug/acpiphp_glue.c

@@ -304,13 +304,6 @@ static acpi_status register_slot(acpi_handle handle, u32 lvl, void *data,
 	if (acpi_has_method(handle, "_STA"))
 		newfunc->flags |= FUNC_HAS_STA;
 
-	/*
-	 * Dock stations' notify handler should be used for dock devices instead
-	 * of the common one, so clear hp.event in their contexts.
-	 */
-	if (acpi_has_method(handle, "_DCK"))
-		context->hp.event = NULL;
-
 	acpi_unlock_hp_context();
 
 	/* search for objects that share the same slot */