examples/nvme: fix memory leaks of arbitration case

The ns_ctxs of worker_thread are organised as a list, so they
should be freed totally.

Change-Id: I348cacb12c338dfe0df100e1dc3de7b9f95bfda1
Signed-off-by: JinYu <jin.yu@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/458036
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

examples/nvme/arbitration/arbitration.c

@@ -434,8 +434,16 @@ cleanup(uint32_t task_count)
 	};
 
 	while (worker) {
+		struct ns_worker_ctx *ns_ctx = worker->ns_ctx;
+
+		/* ns_worker_ctx is a list in the worker */
+		while (ns_ctx) {
+			struct ns_worker_ctx *next_ns_ctx = ns_ctx->next;
+			free(ns_ctx);
+			ns_ctx = next_ns_ctx;
+		}
+
 		next_worker = worker->next;
-		free(worker->ns_ctx);
 		free(worker);
 		worker = next_worker;
 	};