i40e: fix unrecognized FCOE EOF case

Because i40e_fcoe_ctxt_eof should never be called without
i40e_fcoe_eof_is_supported being called first, the EOF in fcoe_ctxt_eof
should always be valid and therefore we do not need to print an error
if it is not valid.

However, a WARN ON to easily catch any calls to i40e_fcoe_ctxt_eof that
aren't preceded with a call to i40e_fcoe_eof_is_supported is helpful.

Change-ID: I3b536b1981ec0bce80576a74440b7dea3908bdb9
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_fcoe.c

@@ -118,7 +118,7 @@ static inline int i40e_fcoe_fc_eof(struct sk_buff *skb, u8 *eof)
  *
  * The FC EOF is converted to the value understood by HW for descriptor
  * programming. Never call this w/o calling i40e_fcoe_eof_is_supported()
- * first.
+ * first and that already checks for all supported valid eof values.
  **/
 static inline u32 i40e_fcoe_ctxt_eof(u8 eof)
 {
@@ -132,9 +132,12 @@ static inline u32 i40e_fcoe_ctxt_eof(u8 eof)
 	case FC_EOF_A:
 		return I40E_TX_DESC_CMD_L4T_EOFT_EOF_A;
 	default:
-		/* FIXME: still returns 0 */
-		pr_err("Unrecognized EOF %x\n", eof);
-		return 0;
+		/* Supported valid eof shall be already checked by
+		 * calling i40e_fcoe_eof_is_supported() first,
+		 * therefore this default case shall never hit.
+		 */
+		WARN_ON(1);
+		return -EINVAL;
 	}
 }