wifi: brcmfmac: clarify unmodifiable headroom log message

Replace misleading log "insufficient headroom (0)" with more clear
"unmodifiable headroom".

Signed-off-by: Alex Shumsky <[email protected]>
Acked-by: Arend van Spriel <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: alex3d

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

@@ -327,8 +327,8 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
 	if (skb_headroom(skb) < drvr->hdrlen || skb_header_cloned(skb)) {
 		head_delta = max_t(int, drvr->hdrlen - skb_headroom(skb), 0);
 
-		brcmf_dbg(INFO, "%s: insufficient headroom (%d)\n",
-			  brcmf_ifname(ifp), head_delta);
+		brcmf_dbg(INFO, "%s: %s headroom\n", brcmf_ifname(ifp),
+			  head_delta ? "insufficient" : "unmodifiable");
 		atomic_inc(&drvr->bus_if->stats.pktcowed);
 		ret = pskb_expand_head(skb, ALIGN(head_delta, NET_SKB_PAD), 0,
 				       GFP_ATOMIC);