of: unittest: Fix overlay type in apply/revert check

The removal check in of_unittest_apply_revert_overlay_check()
always uses the platform device overlay type, while it should use the
actual overlay type, as passed as a parameter to the function.

This has no impact on any current test, as all tests calling
of_unittest_apply_revert_overlay_check() use the platform device overlay
type.

Fixes: d5e7550 ("of: unitest: Add I2C overlay unit tests.")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/ba0234c41ba808f10112094f88792beeb6dbaedf.1690533838.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>

Author: geertu

drivers/of/unittest.c

@@ -2213,7 +2213,7 @@ static int __init of_unittest_apply_revert_overlay_check(int overlay_nr,
 	of_unittest_untrack_overlay(save_ovcs_id);
 
 	/* unittest device must be again in before state */
-	if (of_unittest_device_exists(unittest_nr, PDEV_OVERLAY) != before) {
+	if (of_unittest_device_exists(unittest_nr, ovtype) != before) {
 		unittest(0, "%s with device @\"%s\" %s\n",
 				overlay_name_from_nr(overlay_nr),
 				unittest_path(unittest_nr, ovtype),