ixgbevf: Add lock around ixgbevf_reinit_locked call

The function ixgbevf_reinit_locked() assumes you have the rtnl lock
however we didn't when calling from the service task.  This patch
corrects that.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c

@@ -2779,7 +2779,9 @@ static void ixgbevf_reset_subtask(struct ixgbevf_adapter *adapter)
 
 	adapter->tx_timeout_count++;
 
+	rtnl_lock();
 	ixgbevf_reinit_locked(adapter);
+	rtnl_unlock();
 }
 
 /**