Merge branch 'bpf-Minor-fix-in-bpf_convert_ctx_access'

Daniel Borkmann says:

====================
bpf: Minor fix in bpf_convert_ctx_access

First one was found while trying to compile the kernel
with !CONFIG_NET_RX_BUSY_POLL.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>