kernel/power/energy_model.c: fix memory leak with using debugfs_lookup()

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Link: https://lore.kernel.org/r/20230202151515.2309543-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/power/energy_model.c

@@ -87,10 +87,7 @@ static void em_debug_create_pd(struct device *dev)
 
 static void em_debug_remove_pd(struct device *dev)
 {
-	struct dentry *debug_dir;
-
-	debug_dir = debugfs_lookup(dev_name(dev), rootdir);
-	debugfs_remove_recursive(debug_dir);
+	debugfs_lookup_and_remove(dev_name(dev), rootdir);
 }
 
 static int __init em_debug_init(void)