driver core: fix using 'ret' variable in unregister_dynamic_debug_module

The 'ret' variable is assigned, but not used in the return statement. Fix this.

Signed-off-by: Johann Felix Soden <[e-mail]>
Acked-by: Jason Baron <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

lib/dynamic_printk.c

···
 	nr_entries--;
 out:
 	up(&debug_list_mutex);
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(unregister_dynamic_debug_module);