selftests/bpf: Correctly display subtest skip status

In skip_account(), test->skip_cnt is set to 0 at the end, this makes next print
statement never display SKIP status for the subtest. This patch moves the
accounting logic after the print statement, fixing the issue.

This patch also added SKIP status display for normal tests.

Signed-off-by: Yucong Sun <fallentree@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817044732.3263066-3-fallentree@fb.com