sc1200_wdt: Fix oops

If loaded with isapnp = 0 the driver explodes. This is catching
people out now and then. What should happen in the working case is
a complete mystery and the code appears terminally confused, but we
can at least make the error path work properly.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Partially-Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=53991

drivers/watchdog/sc1200wdt.c

@@ -409,8 +409,9 @@ static int __init sc1200wdt_init(void)
 #if defined CONFIG_PNP
 	/* now that the user has specified an IO port and we haven't detected
 	 * any devices, disable pnp support */
-	isapnp = 0;
+	if (isapnp)
 		pnp_unregister_driver(&scl200wdt_pnp_driver);
+	isapnp = 0;
 #endif
 
 	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {