libnftnl: constify object arguments to various functions

flow table support needs constant object arguments to printing functions
to avoid ugly casts. While at it, also constify object arguments to message
construction, destructor and a few helper functions.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/libnftnl/trace.h b/include/libnftnl/trace.h
index 674bc16..18ab0c3 100644
--- a/include/libnftnl/trace.h
+++ b/include/libnftnl/trace.h
@@ -35,7 +35,7 @@ enum nftnl_trace_attr {
 struct nftnl_trace;
 
 struct nftnl_trace *nftnl_trace_alloc(void);
-void nftnl_trace_free(struct nftnl_trace *trace);
+void nftnl_trace_free(const struct nftnl_trace *trace);
 
 bool nftnl_trace_is_set(const struct nftnl_trace *trace, uint16_t type);