Pull block core fix from Jens Axboe:
"A commit in the previous pull request introduce a regression. So far
only observed on qemu-sparc64, but it's a general bug. Please pull
this single fix to rectify that, thanks"
[ And it turns out that it's been seen outside of that qemu-sparc64
case, and is easy to trigger with small number of CPUs and blk-mq
enabled by default - Linus ]
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: fix iteration of busy bitmap
e076b7c134