After commit 73b62bd085f4737679ea9afc7867fa5f99ba7d1b ("virtio-net:
remove the warning before XDP linearizing"), there's no users for
bpf_warn_invalid_xdp_buffer(), so remove it. This is a revert for
commit f23bc46c30ca5ef58b8549434899fcbac41b2cfc.
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: John Fastabend <john.r.fastabend@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>