Pull md fixes from Neil Brown:
"Some md fixes for 4.2
Several are tagged for -stable.
A few aren't because they are not very, serious or because they are in
the 'experimental' cluster code"
* tag 'md/4.2-fixes' of git://neil.brown.name/md:
md/raid5: clear R5_NeedReplace when no longer needed.
Fix read-balancing during node failure
md-cluster: fix bitmap sub-offset in bitmap_read_sb
md: Return error if request_module fails and returns positive value
md: Skip cluster setup in case of error while reading bitmap
md/raid1: fix test for 'was read error from last working device'.
md: Skip cluster setup for dm-raid
md: flush ->event_work before stopping array.
md/raid10: always set reshape_safe when initializing reshape_position.
md/raid5: avoid races when changing cache size.