Merge branch 'bpf-nfp-codegen-fixes'

Jiong Wang says:

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Code-gen for BPF_ALU | BPF_XOR | BPF_K is wrong when imm is -1,
also high 32-bit of 64-bit register should always be cleared.

This set fixed both bugs.
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Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>