[PATCH v2] conntrack: fix build with kernel 5.15 and musl

[Robert Marko <robimarko@gmail.com>]

Currently, with kernel 5.15 headers and musl building is failing with
redefinition errors due to a conflict between the kernel and musl headers.

Musl is able to suppres the conflicting kernel header definitions if they
are included after the standard libc ones, however since ICMP definitions
were moved into a separate internal header to avoid duplication this has
stopped working and is breaking the builds.

It seems that the issue is that <netinet/in.h> which contains the UAPI
suppression defines is included in the internal.h header and not in the
proto.h which actually includes the kernel ICMP headers and thus UAPI
supression defines are not present.

Solve this by moving the <netinet/in.h> include before the ICMP kernel
includes in the proto.h

Fixes: bc1cb4b11403 ("conntrack: Move icmp request>reply type mapping to common file")
Signed-off-by: Robert Marko <robimarko@gmail.com>
---
Changes in v2:
* Add the forgoten fixes short hash
---
 include/internal/internal.h | 1 -
 include/internal/proto.h    | 1 +
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/internal/internal.h b/include/internal/internal.h
index 2ef8a90..7cd7c44 100644
--- a/include/internal/internal.h
+++ b/include/internal/internal.h
@@ -14,7 +14,6 @@
 #include <arpa/inet.h>
 #include <time.h>
 #include <errno.h>
-#include <netinet/in.h>
 
 #include <libnfnetlink/libnfnetlink.h>
 #include <libnetfilter_conntrack/libnetfilter_conntrack.h>
diff --git a/include/internal/proto.h b/include/internal/proto.h
index 40e7bfe..60a5f4e 100644
--- a/include/internal/proto.h
+++ b/include/internal/proto.h
@@ -2,6 +2,7 @@
 #define _NFCT_PROTO_H_
 
 #include <stdint.h>
+#include <netinet/in.h>
 #include <linux/icmp.h>
 #include <linux/icmpv6.h>
 
-- 
2.35.1