mfd: kempld: Drop duplicate NULL check in ->exit()

Since platform_device_unregister() is NULL-aware, we don't need
to duplicate this check. Remove it and fold the rest of the code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240223195113.880121-6-andriy.shevchenko@linux.intel.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/kempld-core.c

@@ -895,9 +895,7 @@ static int __init kempld_init(void)
 
 static void __exit kempld_exit(void)
 {
-	if (kempld_pdev)
-		platform_device_unregister(kempld_pdev);
-
+	platform_device_unregister(kempld_pdev);
 	platform_driver_unregister(&kempld_driver);
 }