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/apparmor/lsm.c b/security/apparmor/lsm.c
index b760fe0..7ae5405 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -250,7 +250,7 @@
 	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
 }
 
-static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
+static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
 			       umode_t mode)
 {
 	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
@@ -262,7 +262,7 @@
 	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
 }
 
-static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
+static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
 			       umode_t mode, unsigned int dev)
 {
 	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
@@ -273,7 +273,7 @@
 	return common_perm_path(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE);
 }
 
-static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
+static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
 				 const char *old_name)
 {
 	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,