sfc: fix dereference of table before it is null checked

Currently pointer table is being dereferenced on a null check of
table->must_restore_filters before it is being null checked, leading
to a potential null pointer dereference issue. Fix this by null
checking table before dereferencing it when checking for a null
table->must_restore_filters.

Addresses-Coverity: ("Dereference before null check")
Fixes: e4fe938cff04 ("sfc: move 'must restore' flags out of ef10-specific nic_data")
Signed-off-by: Colin Ian King <[e-mail]>
Acked-by: Edward Cree <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/sfc/mcdi_filters.c

···
 
 	WARN_ON(!rwsem_is_locked(&efx->filter_sem));
 
-	if (!table->must_restore_filters)
-		return;
-
-	if (!table)
+	if (!table || !table->must_restore_filters)
 		return;
 
 	down_write(&table->lock);