Staging: hv: vmbus: Embed the state needed to close the channel

Now, embed the state needed to close the channel - so we would not have to
allocate memory in the channel close path.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NAbhishek Kane <v-abkane@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/hyperv.h

@@ -569,6 +569,11 @@ struct vmbus_channel_msginfo {
 	unsigned char msg[0];
 };
 
+struct vmbus_close_msg {
+	struct vmbus_channel_msginfo info;
+	struct vmbus_channel_close_channel msg;
+};
+
 struct vmbus_channel {
 	struct list_head listentry;
 
@@ -601,6 +606,8 @@ struct vmbus_channel {
 	spinlock_t inbound_lock;
 	struct workqueue_struct *controlwq;
 
+	struct vmbus_close_msg close_msg;
+
 	/* Channel callback are invoked in this workqueue context */
 	/* HANDLE dataWorkQueue; */