Pull xarray fixes from Matthew Wilcox:
- Fix a bug encountered by people using bittorrent where they'd get
NULL pointer dereferences on page cache lookups when using XFS
- Two documentation fixes
* tag 'xarray-6.6' of git://git.infradead.org/users/willy/xarray:
idr: fix param name in idr_alloc_cyclic() doc
xarray: Document necessary flag in alloc functions
XArray: Do not return sibling entries from xa_load()