brcmfmac: print errors if creating interface fails

This is helpful for debugging. Without this all I was getting from "iw"
command on failed creating of P2P interface was:
> command failed: Too many open files in system (-23)
Signed-off-by: NRafal Milecki <zajec5@gmail.com>
[arend@broadcom.com: reduce error prints upon iface creation]
Signed-off-by: NArend van Spriel <arend@broadcom.com>
Reviewed-by: NJulian Calaby <julian.calaby@gmail.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

@@ -684,20 +684,24 @@ static struct wireless_dev *brcmf_cfg80211_add_iface(struct wiphy *wiphy,
 		return ERR_PTR(-EOPNOTSUPP);
 	case NL80211_IFTYPE_AP:
 		wdev = brcmf_ap_add_vif(wiphy, name, flags, params);
-		if (!IS_ERR(wdev))
-			brcmf_cfg80211_update_proto_addr_mode(wdev);
-		return wdev;
+		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
 	case NL80211_IFTYPE_P2P_GO:
 	case NL80211_IFTYPE_P2P_DEVICE:
 		wdev = brcmf_p2p_add_vif(wiphy, name, name_assign_type, type, flags, params);
-		if (!IS_ERR(wdev))
-			brcmf_cfg80211_update_proto_addr_mode(wdev);
-		return wdev;
+		break;
 	case NL80211_IFTYPE_UNSPECIFIED:
 	default:
 		return ERR_PTR(-EINVAL);
 	}
+
+	if (IS_ERR(wdev))
+		brcmf_err("add iface %s type %d failed: err=%d\n",
+			  name, type, (int)PTR_ERR(wdev));
+	else
+		brcmf_cfg80211_update_proto_addr_mode(wdev);
+
+	return wdev;
 }
 
 static void brcmf_scan_config_mpc(struct brcmf_if *ifp, int mpc)

drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c

@@ -2030,8 +2030,6 @@ static int brcmf_p2p_request_p2p_if(struct brcmf_p2p_info *p2p,
 
 	err = brcmf_fil_iovar_data_set(ifp, "p2p_ifadd", &if_request,
 				       sizeof(if_request));
-	if (err)
-		return err;
 
 	return err;
 }