mem: fix cleanup after incomplete initialization
mem: fix cleanup after incomplete initialization

In case of EAL initialization failure rte_eal_memory_detach() may be
called before mapping memory configuration, which in this case points
to the static structure. Attempt to unmap it yields error:

    EAL: Could not unmap shared memory config: Invalid argument

Skip unmapping memory configuration if it's not yet shared.

Fixes: dfbc61a2f9a6 ("mem: detach memsegs on cleanup")

Reported-by: David Marchand <f28529695cfa9e3e1eb84e7072aa626af4abb18e@redhat.com>
Signed-off-by: Dmitry Kozlyuk <622f8c4298455ea0ac8bf96da29b254c86170938@gmail.com>
Acked-by: Anatoly Burakov <814e00d8f6e4e81b7ccc7e3e5a0bfec0078f0203@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk