vhost: fix malloc in rte_vhost_get_mem_table

Amount of allocated memory was too small, causing buffer overflow.

Change-Id: Ib43e0a9040f594fed0a8c5660a45aeb07e4400c7
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>

lib/vhost/rte_vhost_17_05/vhost.c

@@ -369,7 +369,7 @@ rte_vhost_get_mem_table(int vid, struct rte_vhost_memory **mem)
 		return -1;
 
 	size = dev->mem->nregions * sizeof(struct rte_vhost_mem_region);
-	m = malloc(size);
+	m = malloc(sizeof(struct rte_vhost_memory) + size);
 	if (!m)
 		return -1;