Staging: hv: vmbus: Get rid of the ext field in struct hv_device

Now that we have eliminated all uses of the ext field in struct hv_device,
get rid of the ext field.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/hv/hyperv.h b/drivers/staging/hv/hyperv.h
index 91e557b..76e2ddd 100644
--- a/drivers/staging/hv/hyperv.h
+++ b/drivers/staging/hv/hyperv.h
@@ -827,9 +827,6 @@
 	struct device device;
 
 	struct vmbus_channel *channel;
-
-	/* Device extension; */
-	void *ext;
 };