[PATCH bpf-next] bpf: hide the unused 'off' variable

[YueHaibing]

The local variable is only used while CONFIG_IPV6 enabled

net/core/filter.c: In function ‘sk_msg_convert_ctx_access’:
net/core/filter.c:6489:6: warning: unused variable ‘off’ [-Wunused-variable]
  int off;
      ^
This puts it into #ifdef.

Fixes: 303def35f64e ("bpf: allow sk_msg programs to read sock fields")
Signed-off-by: YueHaibing <yuehaib...@huawei.com>
---
 net/core/filter.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 24e6ce8..0ce93ed 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6486,7 +6486,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type 
type,
                                     struct bpf_prog *prog, u32 *target_size)
 {
        struct bpf_insn *insn = insn_buf;
+#if IS_ENABLED(CONFIG_IPV6)
        int off;
+#endif
 
        switch (si->off) {
        case offsetof(struct sk_msg_md, data):
-- 
2.7.0