[XFS] fix the noquota mount option

Noquota should clear all mount options, and not just user and group quota.
Probably doesn't matter very much in real life.

SGI-PV: 987246

SGI-Modid: xfs-linux-melb:xfs-kern:32372a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>