[PATCH 1/2 v2 net-next] thunderbolt: Fix a couple right shifting to zero bugs

[Dan Carpenter]

The problematic code looks like this:

        res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
        res_seq >>= TB_XDOMAIN_SN_SHIFT;

TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
going to result in zero.  The fix is to declare these variables as u32.

Fixes: d1ff70241a27 ("thunderbolt: Add support for XDomain discovery protocol")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
v2: I accidentally sent this through the wrong list, so I'm resending to
    netdev.  Also Mika asked me to split it up because the Fixes tags
    are different for these patches.

diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index 138027537d29..ff8d91189e99 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -56,7 +56,7 @@ static bool tb_xdomain_match(const struct tb_cfg_request *req,
        case TB_CFG_PKG_XDOMAIN_RESP: {
                const struct tb_xdp_header *res_hdr = pkg->buffer;
                const struct tb_xdp_header *req_hdr = req->request;
-               u8 req_seq, res_seq;
+               u32 req_seq, res_seq;
 
                if (pkg->frame.size < req->response_size / 4)
                        return false;
@@ -476,7 +476,7 @@ static void tb_xdp_handle_request(struct work_struct *work)
        struct tb_ctl *ctl = tb->ctl;
        const uuid_t *uuid;
        int ret = 0;
-       u8 sequence;
+       u32 sequence;
        u64 route;
 
        route = ((u64)xhdr->route_hi << 32 | xhdr->route_lo) & ~BIT_ULL(63);