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>
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 5148c63..0424ee1 100644
--- a/fs/overlayfs/inode.c
+++ b/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;