fuse: pull iov_iter initializations up

... to fuse_direct_{read,write}().  ->direct_IO() path uses the
iov_iter passed by the caller instead.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --cc fs/fuse/cuse.c
Simple merge

diff --cc fs/fuse/file.c
Simple merge

diff --cc fs/fuse/fuse_i.h
Simple merge