ovl: make oip->index bool

ovl_get_inode() uses oip->index as a bool value, not as a pointer.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/inode.c

@@ -908,7 +908,7 @@ struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir)
  * Does overlay inode need to be hashed by lower inode?
  */
 static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
-			     struct dentry *lower, struct dentry *index)
+			     struct dentry *lower, bool index)
 {
 	struct ovl_fs *ofs = sb->s_fs_info;
 

fs/overlayfs/overlayfs.h

@@ -424,7 +424,7 @@ struct ovl_inode_params {
 	struct inode *newinode;
 	struct dentry *upperdentry;
 	struct ovl_path *lowerpath;
-	struct dentry *index;
+	bool index;
 	unsigned int numlower;
 	char *redirect;
 	struct dentry *lowerdata;