xenvirt: fix reference to old mbuf field
xenvirt: fix reference to old mbuf field

Since commit 08b563ffb19 ("mbuf: replace data pointer by an offset"),
data is not an mbuf field anymore.

Signed-off-by: Sergio Gonzalez Monroy <efb28dd1236fe58fb57f933212eddfe89b9da704@intel.com>
Acked-by: Thomas Monjalon <ee2fa8b2681c737f775687e475dcbf2028a412f1@6wind.com>

phermansson/dpdk,phermansson/dpdk,phermansson/dpdk,phermansson/dpdk