xfs: remove unused parameter from xfs_reclaim_inodes

The noblock parameter of xfs_reclaim_inodes is only ever set to zero. Remove
it and all the conditional code that is never executed.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>