[v1.20.x] prov/shm: Fix coverity issue about resource leak

Sock variable handle goes out of scope and leaks the handle.
This cleans it up properly.

Signed-off-by: Zach Dworkin <zachary.dworkin@intel.com>
(cherry picked from commit e6bc224)

prov/shm/src/smr_ep.c

@@ -1037,8 +1037,10 @@ static void *smr_start_listener(void *args)
 					ep->sock_info->peers[id].device_fds =
 						calloc(ep->sock_info->nfds,
 							sizeof(*ep->sock_info->peers[id].device_fds));
-					if (!ep->sock_info->peers[id].device_fds)
+					if (!ep->sock_info->peers[id].device_fds) {
+						close(sock);
 						goto out;
+					}
 				}
 				memcpy(ep->sock_info->peers[id].device_fds,
 				       peer_fds, sizeof(*peer_fds) *