libbpf-tools: remove now unnecessary bump_memlock_rlimit()

libbpf will now automatically decide whether it's necessary, and if yes,
will do it on behalf of the application.

All the subsequet tools should make sure to set:

```
libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
```

Signed-off-by: Andrii Nakryiko <[email protected]>

libbpf-tools/trace_helpers.c

@@ -967,16 +967,6 @@ unsigned long long get_ktime_ns(void)
  return ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec;
 }
 
-int bump_memlock_rlimit(void)
-{
- struct rlimit rlim_new = {
- .rlim_cur = RLIM_INFINITY,
- .rlim_max = RLIM_INFINITY,
- };
-
- return setrlimit(RLIMIT_MEMLOCK, &rlim_new);
-}
-
 bool is_kernel_module(const char *name)
 {
  bool found = false;
@@ -1007,20 +997,22 @@ bool fentry_exists(const char *name, const char *mod)
  const struct btf_type *type;
  const struct btf_enum *e;
  char sysfs_mod[80];
- int id = -1, i;
+ int id = -1, i, err;
 
  base = btf__parse(sysfs_vmlinux, NULL);
- if (libbpf_get_error(base)) {
+ if (!base) {
+ err = -errno;
  fprintf(stderr, "failed to parse vmlinux BTF at '%s': %s\n",
- sysfs_vmlinux, strerror(-libbpf_get_error(base)));
+ sysfs_vmlinux, strerror(-err));
  goto err_out;
  }
  if (mod && module_btf_exists(mod)) {
  snprintf(sysfs_mod, sizeof(sysfs_mod), "/sys/kernel/btf/%s", mod);
  btf = btf__parse_split(sysfs_mod, base);
- if (libbpf_get_error(btf)) {
+ if (!btf) {
+ err = -errno;
  fprintf(stderr, "failed to load BTF from %s: %s\n",
- sysfs_mod, strerror(-libbpf_get_error(btf)));
+ sysfs_mod, strerror(-err));
  btf = base;
  base = NULL;
  }

libbpf-tools/trace_helpers.h

@@ -58,7 +58,6 @@ void print_linear_hist(unsigned int *vals, int vals_size, unsigned int base,
  unsigned int step, const char *val_type);
 
 unsigned long long get_ktime_ns(void);
-int bump_memlock_rlimit(void);
 
 bool is_kernel_module(const char *name);