sfc: constify pci_error_handlers structures

This pci_error_handlers structure is never modified, like all the other
pci_error_handlers structures, so declare it as const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/efx.c

@@ -3422,7 +3422,7 @@ static void efx_io_resume(struct pci_dev *pdev)
  * with our request for slot reset the mmio_enabled callback will never be
  * called, and the link_reset callback is not used by AER or EEH mechanisms.
  */
-static struct pci_error_handlers efx_err_handlers = {
+static const struct pci_error_handlers efx_err_handlers = {
 	.error_detected = efx_io_error_detected,
 	.slot_reset	= efx_io_slot_reset,
 	.resume		= efx_io_resume,