wifi: mac80211: remove tx_handlers_drop debugfs stats

Commit 906a5a8c7152 ("wifi: mac80211: add tx_handlers_drop statistics
to ethtool") added a tx_handlers_drop counter to ethtool stats.
During review [1], Johannes noted that the existing debugfs counter
is now redundant. Remove the debugfs stat to avoid duplication and
streamline statistics reporting.

Link: https://lore.kernel.org/linux-wireless/[e-mail]/ # [1]
Signed-off-by: Sarika Sharma <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Johannes Berg <[e-mail]>

net/mac80211/debugfs.c

···
 	DEBUGFS_STATS_ADD(dot11ReceivedFragmentCount);
 	DEBUGFS_STATS_ADD(dot11MulticastReceivedFrameCount);
 	DEBUGFS_STATS_ADD(dot11TransmittedFrameCount);
-	DEBUGFS_STATS_ADD(tx_handlers_drop);
 	DEBUGFS_STATS_ADD(tx_handlers_queued);
 	DEBUGFS_STATS_ADD(tx_handlers_drop_wep);
 	DEBUGFS_STATS_ADD(tx_handlers_drop_not_assoc);

net/mac80211/ieee80211_i.h

···
 	u32 dot11TransmittedFrameCount;
 
 	/* TX/RX handler statistics */
-	unsigned int tx_handlers_drop;
 	unsigned int tx_handlers_queued;
 	unsigned int tx_handlers_drop_wep;
 	unsigned int tx_handlers_drop_not_assoc;

net/mac80211/tx.c

···
  txh_done:
 	if (unlikely(res == TX_DROP)) {
 		tx->sdata->tx_handlers_drop++;
-		I802_DEBUG_INC(tx->local->tx_handlers_drop);
 		if (tx->skb)
 			ieee80211_free_txskb(&tx->local->hw, tx->skb);
 		else
···
  txh_done:
 	if (unlikely(res == TX_DROP)) {
 		tx->sdata->tx_handlers_drop++;
-		I802_DEBUG_INC(tx->local->tx_handlers_drop);
 		if (tx->skb)
 			ieee80211_free_txskb(&tx->local->hw, tx->skb);
 		else