fm10k: add call to fm10k_clean_all_rx_rings in fm10k_down

This prevents a memory leak in fm10k_set_ringparams. The leak occurs
because we go down, change ring parameters, and then come up. However,
fm10k_down on its own is not clearing the Rx rings. Since fm10k_up
assumes the rings are clean we basically drop the buffers and leak a
bunch of memory. Eventually we hit dirty page faults and reboot the
system. This issue does not occur elsewhere because other flows that
involve fm10k_down go through fm10k_close which immediately called
fm10k_free_all_rx_resources which properly cleans the rings.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NKrishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k_pci.c

@@ -1559,6 +1559,7 @@ void fm10k_down(struct fm10k_intfc *interface)
 
 	/* free any buffers still on the rings */
 	fm10k_clean_all_tx_rings(interface);
+	fm10k_clean_all_rx_rings(interface);
 }
 
 /**