ocfs2: Sync max_inline_data_with_xattr from tools.

In ocfs2-tools, we have added ocfs2_max_inline_data_with_xattr,
so add it in the kernel's ocfs2_fs.h.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>