ACPI dock: support multiple ACPI dock devices

There may be multiple ACPI dock devices exist in ACPI namespace
and we should probe all of them.
http://bugzilla.kernel.org/show_bug.cgi?id=15521

CC: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/dock.c

@@ -1025,13 +1025,10 @@ static int dock_remove(struct dock_station *ds)
 static acpi_status
 find_dock(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
-	acpi_status status = AE_OK;
-
 	if (is_dock(handle))
-		if (dock_add(handle) >= 0)
-			status = AE_CTRL_TERMINATE;
+		dock_add(handle);
 
-	return status;
+	return AE_OK;
 }
 
 static acpi_status