selftests/bpf: Also print test name in subtest status message

This patch add test name in subtest status message line, making it possible to
grep ':OK' in the output to generate a list of passed test+subtest names, which
can be processed to generate argument list to be used with "-a", "-d" exact
string matching.

Example:

#1/1 align/mov:OK
..
#1/12 align/pointer variable subtraction:OK
#1 align:OK

Signed-off-by: Yucong Sun <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/testing/selftests/bpf/test_progs.c

···
 
 	dump_test_log(test, sub_error_cnt);
 
-	fprintf(env.stdout, "#%d/%d %s:%s\n",
-	       test->test_num, test->subtest_num, test->subtest_name,
+	fprintf(env.stdout, "#%d/%d %s/%s:%s\n",
+	       test->test_num, test->subtest_num, test->test_name, test->subtest_name,
 	       sub_error_cnt ? "FAIL" : (test->skip_cnt ? "SKIP" : "OK"));
 
 	if (sub_error_cnt)