constify security_path_{mkdir,mknod,symlink}

... as well as unix_mknod() and may_o_create()

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 322912c..919fb4f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1361,13 +1361,13 @@
 
 #ifdef CONFIG_SECURITY_PATH
 	int (*path_unlink)(const struct path *dir, struct dentry *dentry);
-	int (*path_mkdir)(struct path *dir, struct dentry *dentry,
+	int (*path_mkdir)(const struct path *dir, struct dentry *dentry,
 				umode_t mode);
 	int (*path_rmdir)(const struct path *dir, struct dentry *dentry);
-	int (*path_mknod)(struct path *dir, struct dentry *dentry,
+	int (*path_mknod)(const struct path *dir, struct dentry *dentry,
 				umode_t mode, unsigned int dev);
 	int (*path_truncate)(const struct path *path);
-	int (*path_symlink)(struct path *dir, struct dentry *dentry,
+	int (*path_symlink)(const struct path *dir, struct dentry *dentry,
 				const char *old_name);
 	int (*path_link)(struct dentry *old_dentry, struct path *new_dir,
 				struct dentry *new_dentry);