libbpf: fix typo in bpf_attach_xdp()
libbpf: fix typo in bpf_attach_xdp()

tuxology/bcc,tuxology/bcc,brendangregg/bcc,iovisor/bcc,brendangregg/bcc,tuxology/bcc,brendangregg/bcc,mcaleavya/bcc,tuxology/bcc,mcaleavya/bcc,mcaleavya/bcc,iovisor/bcc,tuxology/bcc,iovisor/bcc,iovisor/bcc,brendangregg/bcc,mcaleavya/bcc,mcaleavya/bcc,iovisor/bcc,brendangregg/bcc