ipc: fix undefined behavior in no-shconf mode

ipc: fix undefined behavior in no-shconf mode

In no-shconf mode the rte_mp_request_sync() wasn't initializing
the `reply` parameter, which contained e.g. a number of sent
requests. Callers of rte_mp_request_sync() might check that
param afterwards and might read potentially unitialized memory.

The no-shconf check that makes us return early (with rc = 0) was
placed before the `reply` initialization. Fix this by making the
`reply` initialization occur first.

Fixes: 5848e3d2813c ("ipc: support --no-shconf mode")
Cc: stable@dpdk.org
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>