Compilation fails on Fedora 43 with Kernel 6.18.5-200 (flowi4_tos)

[M1cha]

It looks like the fix in #441 does not work for fedora, due to the macro arguments:

  CC [M]  rfc7915/6to4.o
rfc7915/6to4.c: In function 'compute_flowix64':
rfc7915/6to4.c:209:14: error: 'struct flowi4' has no member named 'flowi4_tos'
rfc7915/6to4.c: In function 'compute_flowix64':
rfc7915/6to4.c:209:14: error: 'struct flowi4' has no member named 'flowi4_tos'
  209 |         flow4->flowi4_tos = xlat_tos(&state->jool.globals, hdr6);
      |              ^~
  209 |         flow4->flowi4_tos = xlat_tos(&state->jool.globals, hdr6);
      |              ^~
rfc7915/6to4.c: In function 'ttp64_ipv4_external':
rfc7915/6to4.c:655:26: error: 'struct flowi4' has no member named 'flowi4_tos'
  655 |         hdr4->tos = flow4->flowi4_tos;
      |                          ^~
rfc7915/6to4.c: In function 'ttp64_ipv4_external':
rfc7915/6to4.c:655:26: error: 'struct flowi4' has no member named 'flowi4_tos'
  655 |         hdr4->tos = flow4->flowi4_tos;
      |                          ^~

These are the contents of version.h:

#define LINUX_VERSION_CODE 397829
#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + ((c) > 255 ? 255 : (c)))
#define LINUX_VERSION_MAJOR 6
#define LINUX_VERSION_PATCHLEVEL 18
#define LINUX_VERSION_SUBLEVEL 5
#define RHEL_MAJOR 10
#define RHEL_MINOR 99
#define RHEL_RELEASE_VERSION(a,b) (((a) << 8) + (b))
#define RHEL_RELEASE_CODE 2659
#define RHEL_RELEASE "0"

[M1cha]

I fixed this (and more errors) in #445.