selftests: drv-net: tso: fix non-tunneled tso6 test case name

selftests: drv-net: tso: fix non-tunneled tso6 test case name

The non-tunneled tso6 test case was showing up as:
ok 8 tso.ipv4

This is because of the way test_builder() uses the inner_ipver arg in
test naming, and how test_info is iterated over in main(). Given that
some tunnels not supported yet, e.g. ipip or sit, only support ipv4 or
ipv6 as the inner network protocol, I think the best fix here is to
call test_builder() in separate branches for tunneled and non-tunneled
tests, and to make supported inner l3 types an explicit attribute of
tunnel test cases.

  # Detected qstat for LSO wire-packets
  TAP version 13
  1..14
  ok 1 tso.ipv4
  # Testing with mangleid enabled
  ok 2 tso.vxlan4_ipv4
  ok 3 tso.vxlan4_ipv6
  # Testing with mangleid enabled
  ok 4 tso.vxlan_csum4_ipv4
  ok 5 tso.vxlan_csum4_ipv6
  # Testing with mangleid enabled
  ok 6 tso.gre4_ipv4
  ok 7 tso.gre4_ipv6
  ok 8 tso.ipv6
  # Testing with mangleid enabled
  ok 9 tso.vxlan6_ipv4
  ok 10 tso.vxlan6_ipv6
  # Testing with mangleid enabled
  ok 11 tso.vxlan_csum6_ipv4
  ok 12 tso.vxlan_csum6_ipv6
  # Testing with mangleid enabled
  ok 13 tso.gre6_ipv4
  ok 14 tso.gre6_ipv6
  # Totals: pass:14 fail:0 xfail:0 xpass:0 skip:0 error:0

Fixes: 0d0f4174f6c8 ("selftests: drv-net: add a simple TSO test")
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20250723184740.4075410-4-daniel.zahka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>