eal: fix mapping leak in secondary process

eal: fix mapping leak in secondary process

Have rte_eal_config_reattach clean up the mapped address which is a valid
address but not the one intended.

Coverity issue: 343439
Fixes: 4e8854ae89fa ("eal: do not panic on shared memory init")
Fixes: b149a7064261 ("eal/freebsd: add config reattach in secondary process")
Cc: stable@dpdk.org
Signed-off-by: Arnon Warshavsky <arnon@qwilt.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>