drivers: hv: vmbus: Fix call msleep using < 20ms

Fixed checkpatch warning: MSLEEP: msleep < 20ms can sleep for up to
20ms; see Documentation/timers/timers-howto.rst

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-7-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/vmbus_drv.c

@@ -2380,7 +2380,7 @@ static int vmbus_bus_suspend(struct device *dev)
 		 * We wait here until the completion of any channel
 		 * offers that are currently in progress.
 		 */
-		msleep(1);
+		usleep_range(1000, 2000);
 	}
 
 	mutex_lock(&vmbus_connection.channel_mutex);