selftest: packetdrill: Set ktap_set_plan properly for single protocol test.

selftest: packetdrill: Set ktap_set_plan properly for single protocol test.

The cited commit forgot to update the ktap_set_plan call.

ktap_set_plan sets the number of tests (KSFT_NUM_TESTS), which must
match the number of executed tests (KTAP_CNT_PASS + KTAP_CNT_SKIP +
KTAP_CNT_XFAIL) in ktap_finished.

Otherwise, the selftest exit()s with 1.

Let's adjust KSFT_NUM_TESTS based on supported protocols.

While at it, misalignment is fixed up.

Fixes: a5c10aa3d1ba ("selftests/net: packetdrill: Support single protocol test.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250927213022.1850048-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>