[XFS] cleanup xfs_mountfs

Remove all the useless flags and code keyed off it in xfs_mountfs.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31831a

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Lachlan McIlroy <[email protected]>
10 files changed