mac80211: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/mac80211/tx.c

@@ -2017,24 +2017,14 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		skb = skb_clone(skb, GFP_ATOMIC);
 		if (skb) {
 			unsigned long flags;
-			int id, r;
+			int id;
 
 			spin_lock_irqsave(&local->ack_status_lock, flags);
-			r = idr_get_new_above(&local->ack_status_frames,
-					      orig_skb, 1, &id);
-			if (r == -EAGAIN) {
-				idr_pre_get(&local->ack_status_frames,
-					    GFP_ATOMIC);
-				r = idr_get_new_above(&local->ack_status_frames,
-						      orig_skb, 1, &id);
-			}
-			if (WARN_ON(!id) || id > 0xffff) {
-				idr_remove(&local->ack_status_frames, id);
-				r = -ERANGE;
-			}
+			id = idr_alloc(&local->ack_status_frames, orig_skb,
+				       1, 0x10000, GFP_ATOMIC);
 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
 
-			if (!r) {
+			if (id >= 0) {
 				info_id = id;
 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 			} else if (skb_shared(skb)) {