set bpf/syscall logging to debug

[rc-vbundage]

The syscall.rs of the bpf library is very spammy on info dumping logs during retries when the system kernel does not support eBPF. The output logged isn't useful for troubleshooting outside a debug context.

Example:

sys_bpf(); cmd: 5; errno: 22; arg_bpf_attr: SizedBpfAttr { bpf_attr: BpfAttr: [2, 0, 0, 0, 2, 0, 0, 0, 64, 44, 106, 1, 0, 0, 0, 0, 160, 223, 115, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 208, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], size: 48 }