igb: Fix potential memory leak in igb_add_ethtool_nfc_entry

Add check for return of igb_update_ethtool_nfc_entry so that in case
of any potential errors the memory alocated for input will be freed.

Fixes: 0e71def2 ("igb: add support of RX network flow classification")
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Arpana Arland <arpanax.arland@intel.com> (A Contingent worker at Intel)
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/igb/igb_ethtool.c

@@ -2978,11 +2978,15 @@ static int igb_add_ethtool_nfc_entry(struct igb_adapter *adapter,
 	if (err)
 		goto err_out_w_lock;
 
-	igb_update_ethtool_nfc_entry(adapter, input, input->sw_idx);
+	err = igb_update_ethtool_nfc_entry(adapter, input, input->sw_idx);
+	if (err)
+		goto err_out_input_filter;
 
 	spin_unlock(&adapter->nfc_lock);
 	return 0;
 
+err_out_input_filter:
+	igb_erase_filter(adapter, input);
 err_out_w_lock:
 	spin_unlock(&adapter->nfc_lock);
 err_out: