af_packet: fix possible memory leak
af_packet: fix possible memory leak

In rte_pmd_init_internals, we are mapping memory but not released
if error occurs it could produce memory leak.
Add unmmap function to release memory.

Signed-off-by: Daniel Mrzyglod <998f22cc3a6ac3535545292178d834b83a4e2a87@intel.com>
Acked-by: Michal Jastrzebski <99bb29f284bc46c0a62a09be83edd00b1cccc1e5@intel.com>
Acked-by: John W. Linville <2a53bac7a5d324865ef46ec4c38b2c0fba1456b4@tuxdriver.com>

mixja/dpdk,venkynv/dpdk-mirror,msune/dpdk,tsphillips/dpdk-fork,msune/dpdk,tsphillips/dpdk-fork,john-mcnamara-intel/dpdk,mixja/dpdk,msune/dpdk,venkynv/dpdk-mirror,tsphillips/dpdk-fork,john-mcnamara-intel/dpdk,venkynv/dpdk-mirror,tsphillips/dpdk-fork,john-mcnamara-intel/dpdk,mixja/dpdk,mixja/dpdk,venkynv/dpdk-mirror,john-mcnamara-intel/dpdk,msune/dpdk