fuse: req use bitops

Finer grained locking will mean there's no single lock to protect
modification of bitfileds in fuse_req.

So move to using bitops.  Can use the non-atomic variants for those which
happen while the request definitely has only one reference.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Ashish Samant <ashish.samant@oracle.com>

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

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

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

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