net: Use g_new() & friends where that makes obvious sense

g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/net/queue.c b/net/queue.c
index f948318..ebbe2bb 100644
--- a/net/queue.c
+++ b/net/queue.c
@@ -62,7 +62,7 @@
 {
     NetQueue *queue;
 
-    queue = g_malloc0(sizeof(NetQueue));
+    queue = g_new0(NetQueue, 1);
 
     queue->opaque = opaque;
     queue->nq_maxlen = 10000;