constify security_path_truncate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index cdee11c..77c3bfd 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1366,7 +1366,7 @@
 	int (*path_rmdir)(struct path *dir, struct dentry *dentry);
 	int (*path_mknod)(struct path *dir, struct dentry *dentry,
 				umode_t mode, unsigned int dev);
-	int (*path_truncate)(struct path *path);
+	int (*path_truncate)(const struct path *path);
 	int (*path_symlink)(struct path *dir, struct dentry *dentry,
 				const char *old_name);
 	int (*path_link)(struct dentry *old_dentry, struct path *new_dir,