net/iavf: fix mbuf release in multi-process

net/iavf: fix mbuf release in multi-process

In the multiple process environment, the subprocess operates on the
shared memory and changes the function pointer of the main process,
resulting in the failure to find the address of the function when main
process releasing, resulting in crash.

Fixes: 319c421f3890 ("net/avf: enable SSE Rx Tx")
Cc: stable@dpdk.org
Signed-off-by: Ke Zhang <ke1x.zhang@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>