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/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index be5b1ae..d447525 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -178,7 +178,7 @@
  *
  * Returns 0 on success, negative value otherwise.
  */
-static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
+static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry,
 			     umode_t mode)
 {
 	struct path path = { parent->mnt, dentry };
@@ -209,7 +209,7 @@
  *
  * Returns 0 on success, negative value otherwise.
  */
-static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
+static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry,
 			       const char *old_name)
 {
 	struct path path = { parent->mnt, dentry };
@@ -226,7 +226,7 @@
  *
  * Returns 0 on success, negative value otherwise.
  */
-static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
+static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry,
 			     umode_t mode, unsigned int dev)
 {
 	struct path path = { parent->mnt, dentry };