aya/bpf
Tw d1b7b024dc bpf: fix a minor bug due to stackid allocation
The type casting introduces an allocation, this will cause compiling failure when linking final bpf target.
So remove this casting to fix this issue.

BTW, the following is the failure I met:

= note: 07:24:12 [ERROR] fatal error: "unable to allocate function return #1"
          PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
          Stack dump:
          0.    Running pass 'Function Pass Manager' on module 'trace_bpf-001a275b17e9eb12'.
          1.    Running pass 'BPF DAG->DAG Pattern Instruction Selection' on function '@_ZN7aya_bpf4maps11stack_trace10StackTrace11get_stackid17h32b649bc3780c0aaE'

Signed-off-by: Tw <wei.tan@intel.com>
..
aya-bpf bpf: fix a minor bug due to stackid allocation
aya-bpf-bindings bpf: don't generate bpf_map_def and fix aya_bpf::bindings overrides
aya-bpf-cty bpf/aya-bpf-cty: target_arch for bpf*-unknown-none was renamed to "bpf"
aya-bpf-macros bpf: add support for BPF_PROG_TYPE_CGROUP_SKB programs
Cargo.toml bpf: add aya-bpf-bindings