selftests/bpf: Use bpf_tracing.h instead of bpf_tcp_helpers.h

The bpf programs that this patch changes require the BPF_PROG macro.
The BPF_PROG macro is defined in the libbpf's bpf_tracing.h.
Some tests include bpf_tcp_helpers.h which includes bpf_tracing.h.
They don't need other things from bpf_tcp_helpers.h other than
bpf_tracing.h. This patch simplifies it by directly including
the bpf_tracing.h.

The motivation of this unnecessary code churn is to retire
the bpf_tcp_helpers.h by directly using vmlinux.h. Right now,
the main usage of the bpf_tcp_helpers.h is the partial kernel
socket definitions (e.g. socket, sock, tcp_sock). While the test
cases continue to grow, fields are kept adding to those partial
socket definitions (e.g. the recent bpf_cc_cubic.c test which
tried to extend bpf_tcp_helpers.c but eventually used the
vmlinux.h instead).

The idea is to retire bpf_tcp_helpers.c and consistently use
vmlinux.h for the tests that require the kernel sockets. This
patch tackles the obvious tests that can directly use bpf_tracing.h
instead of bpf_tcp_helpers.h.

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

tools/testing/selftests/bpf/progs/timer.c

···
 /* Copyright (c) 2021 Facebook */
 #include <linux/bpf.h>
 #include <time.h>
+#include <stdbool.h>
 #include <errno.h>
 #include <bpf/bpf_helpers.h>
-#include "bpf_tcp_helpers.h"
+#include <bpf/bpf_tracing.h>
 
 char _license[] SEC("license") = "GPL";
 struct hmap_elem {

tools/testing/selftests/bpf/progs/timer_failure.c

···
 #include <time.h>
 #include <errno.h>
 #include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
 #include "bpf_misc.h"
-#include "bpf_tcp_helpers.h"
 
 char _license[] SEC("license") = "GPL";
 

tools/testing/selftests/bpf/progs/timer_mim.c

···
 #include <time.h>
 #include <errno.h>
 #include <bpf/bpf_helpers.h>
-#include "bpf_tcp_helpers.h"
+#include <bpf/bpf_tracing.h>
 
 char _license[] SEC("license") = "GPL";
 struct hmap_elem {

tools/testing/selftests/bpf/progs/timer_mim_reject.c

···
 #include <time.h>
 #include <errno.h>
 #include <bpf/bpf_helpers.h>
-#include "bpf_tcp_helpers.h"
+#include <bpf/bpf_tracing.h>
 
 char _license[] SEC("license") = "GPL";
 struct hmap_elem {