btrfs: use unsigned types for constants defined as bit shifts

[ Upstream commit 05a6ec86 ]

The unsigned type is a recommended practice (CWE-190, CWE-194) for bit
shifts to avoid problems with potential unwanted sign extensions.
Although there are no such cases in btrfs codebase, follow the
recommendation.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 1f2889f5 ("btrfs: fix qgroup reservation leak on failure to allocate ordered extent")
Signed-off-by: Sasha Levin <sashal@kernel.org>