Pull three md bugfixes from NeilBrown:
"One of the bugs was introduced in 3.5-rc1. Others have been there for
longer."
* tag 'md-3.5-fixes' of git://neil.brown.name/md:
md/raid1: close some possible races on write errors during resync
md: avoid crash when stopping md array races with closing other open fds.
md: fix bug in handling of new_data_offset