tools: bpftool: use "/proc/self/" i.o. crafting links with getpid()

#include <sys/mount.h>

#include <sys/resource.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/vfs.h>

#include <bpf.h>

	char buf[512];

	ssize_t n;

	snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);

	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);

	n = readlink(path, buf, sizeof(buf));

	if (n < 0) {

	ssize_t n;

	FILE *fdi;

	snprintf(path, sizeof(path), "/proc/%d/fdinfo/%d", getpid(), fd);

	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);

	fdi = fopen(path, "r");

	if (!fdi) {

#include <string.h>

#include <bfd.h>

#include <dis-asm.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <limits.h>

static void get_exec_path(char *tpath, size_t size)

{

	const char *path = "/proc/self/exe";

	ssize_t len;

	char *path;

	snprintf(tpath, size, "/proc/%d/exe", (int) getpid());

	tpath[size - 1] = 0;

	path = strdup(tpath);

	assert(path);

	len = readlink(path, tpath, size - 1);

	assert(len > 0);

	tpath[len] = 0;

	free(path);

}

static int oper_count;