node: check result malloc

Author: SidoShiro

src/network/node.c

@@ -2,6 +2,8 @@
 
 struct node *generate_node(unsigned short id, size_t size) {
     struct node *n = malloc(sizeof(struct node));
+    if (!n)
+        return NULL;
     n->id = id;
     n->size = size;
     n->isleader = 0;