selftests/bpf: fix test_align liveliness expectations

Commit 2589726d ("bpf: introduce bounded loops") caused a change
in the way some registers liveliness is reported in the test_align.
Add missing "_w" to a couple of tests. Note, there are no offset
changes!

Fixes: 2589726d ("bpf: introduce bounded loops")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>