Staging: hv: Fix up memory leak on HvCleanup

Don't assign NULL too early
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/Hv.c

@@ -306,9 +306,9 @@ void HvCleanup(void)
 	DPRINT_ENTER(VMBUS);
 
 	if (gHvContext.SignalEventBuffer) {
+		kfree(gHvContext.SignalEventBuffer);
 		gHvContext.SignalEventBuffer = NULL;
 		gHvContext.SignalEventParam = NULL;
-		kfree(gHvContext.SignalEventBuffer);
 	}
 
 	if (gHvContext.HypercallPage) {