Pull 9p iov_iter fix from Al Viro:
"net/9p abuses iov_iter primitives - it attempts to copy _from_ a
destination-only iov_iter when it handles Rerror arriving in reply to
zero-copy request. Not hard to fix, fortunately.
This is a prereq for the iov_iter_get_pages() work in the second part
of iov_iter series, ended up in a separate branch"
* tag 'pull-work.9p' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
9p: handling Rerror without copy_from_iter_full()