[XFS] kill xfs_rwlock/xfs_rwunlock

We can just use xfs_ilock/xfs_iunlock instead and get rid of the ugly
bhv_vrwlock_t.

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30533a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
6 files changed