[PATCH net-next] sfc: check async completer is !NULL before calling

[Bert Kenward]

Add a NULL check before calling asynchronous MCDI completion functions
during device removal.

Fixes: 7014d7f6 ("sfc: allow asynchronous MCDI without completion function")
Signed-off-by: Bert Kenward <bkenw...@solarflare.com>
---
 drivers/net/ethernet/sfc/mcdi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 9fbc12a..2415209 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -1156,7 +1156,8 @@ void efx_mcdi_flush_async(struct efx_nic *efx)
         * acquired locks in the wrong order.
         */
        list_for_each_entry_safe(async, next, &mcdi->async_list, list) {
-               async->complete(efx, async->cookie, -ENETDOWN, NULL, 0);
+               if (async->complete)
+                       async->complete(efx, async->cookie, -ENETDOWN, NULL, 0);
                list_del(&async->list);
                kfree(async);
        }
-- 
2.7.4