i40e: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -14486,29 +14486,29 @@ static void i40e_print_features(struct i40e_pf *pf)
 
 	i = snprintf(buf, INFO_STRING_LEN, "Features: PF-id[%d]", hw->pf_id);
 #ifdef CONFIG_PCI_IOV
-	i += snprintf(&buf[i], REMAIN(i), " VFs: %d", pf->num_req_vfs);
+	i += scnprintf(&buf[i], REMAIN(i), " VFs: %d", pf->num_req_vfs);
 #endif
-	i += snprintf(&buf[i], REMAIN(i), " VSIs: %d QP: %d",
+	i += scnprintf(&buf[i], REMAIN(i), " VSIs: %d QP: %d",
 		      pf->hw.func_caps.num_vsis,
 		      pf->vsi[pf->lan_vsi]->num_queue_pairs);
 	if (pf->flags & I40E_FLAG_RSS_ENABLED)
-		i += snprintf(&buf[i], REMAIN(i), " RSS");
+		i += scnprintf(&buf[i], REMAIN(i), " RSS");
 	if (pf->flags & I40E_FLAG_FD_ATR_ENABLED)
-		i += snprintf(&buf[i], REMAIN(i), " FD_ATR");
+		i += scnprintf(&buf[i], REMAIN(i), " FD_ATR");
 	if (pf->flags & I40E_FLAG_FD_SB_ENABLED) {
-		i += snprintf(&buf[i], REMAIN(i), " FD_SB");
-		i += snprintf(&buf[i], REMAIN(i), " NTUPLE");
+		i += scnprintf(&buf[i], REMAIN(i), " FD_SB");
+		i += scnprintf(&buf[i], REMAIN(i), " NTUPLE");
 	}
 	if (pf->flags & I40E_FLAG_DCB_CAPABLE)
-		i += snprintf(&buf[i], REMAIN(i), " DCB");
-	i += snprintf(&buf[i], REMAIN(i), " VxLAN");
-	i += snprintf(&buf[i], REMAIN(i), " Geneve");
+		i += scnprintf(&buf[i], REMAIN(i), " DCB");
+	i += scnprintf(&buf[i], REMAIN(i), " VxLAN");
+	i += scnprintf(&buf[i], REMAIN(i), " Geneve");
 	if (pf->flags & I40E_FLAG_PTP)
-		i += snprintf(&buf[i], REMAIN(i), " PTP");
+		i += scnprintf(&buf[i], REMAIN(i), " PTP");
 	if (pf->flags & I40E_FLAG_VEB_MODE_ENABLED)
-		i += snprintf(&buf[i], REMAIN(i), " VEB");
+		i += scnprintf(&buf[i], REMAIN(i), " VEB");
 	else
-		i += snprintf(&buf[i], REMAIN(i), " VEPA");
+		i += scnprintf(&buf[i], REMAIN(i), " VEPA");
 
 	dev_info(&pf->pdev->dev, "%s\n", buf);
 	kfree(buf);