libbpf: 1.2.0 -> 1.2.2

1.2.1: Bug fix release:

Single bug fix (#1) that fixes regression in `perf` tool caused by libbpf
resetting its custom catch-all `SEC()` handler on explicit
`bpf_program__set_type()` call.

Given setting custom `SEC()` handlers is rarely used and pretty
esoteric feature of libbpf, most users should not be affected.

1.2.2: One more fix:

 - Fix (#2) possible double-free in USDT-related libbpf code, which
happens when libbpf runs out of space in `__bpf_usdt_specs` map due
to having too many unique USDT specs. Running out of space can be
mitigated by bumping up `BPF_USDT_MAX_SPEC_CNT` define before including
`bpf/usdt.bpf.h` header in BPF-side code.
This will prevent the double-free as a side effect (and will make it
possible to successfully attach all requested USDTs), which is a
recommended work-around for libbpf versions prior to v1.2.2.

Link: libbpf/libbpf@e4d3827 #1
Link: libbpf/libbpf@f117080 #2

pkgs/os-specific/linux/libbpf/default.nix

@@ -9,13 +9,13 @@
 
 stdenv.mkDerivation rec {
   pname = "libbpf";
-  version = "1.2.0";
+  version = "1.2.2";
 
   src = fetchFromGitHub {
     owner = "libbpf";
     repo = "libbpf";
     rev = "v${version}";
-    sha256 = "sha256-NimK4pdYcai21hZHdP1mBX1MOlNY61iDJ+PDYwpRuVE=";
+    sha256 = "sha256-SDDdz2HKEfzHloLkb0sv5ldTo+1yJDVc9O7nj4Cjznk=";
   };
 
   nativeBuildInputs = [ pkg-config ];