[brcmfmac] Don't issue wrong insufficient headroom warning

We may just have had to clone a packet, and not actually
have run out of headroom.  Only issue warning about headroom
when we actually ran out of headroom.
This removes useless spam about needing 0 more bytes of headroom.

Signed-off-by: Daniel Berlin <dberlin@dberlin.org>

Author: dberlin

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

@@ -326,9 +326,11 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
 	/* Make sure there's enough writeable headroom */
 	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);
+		/* Don't warn unless we actually ran out of headroom vs
+		   had to clone.*/
+		if (head_delta != 0)
+			brcmf_dbg(INFO, "%s: insufficient headroom (%d)\n",
+				  brcmf_ifname(ifp), head_delta);
 		atomic_inc(&drvr->bus_if->stats.pktcowed);
 		ret = pskb_expand_head(skb, ALIGN(head_delta, NET_SKB_PAD), 0,
 				       GFP_ATOMIC);