staging: rtl8192u: Fix return type of ieee80211_xmit

The ndo_start_xmit field in net_device_ops is expected to be of type
netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb, struct net_device *dev).

The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition.

The return type of ieee80211_xmit should be changed from int to
netdev_tx_t.

Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@lists.linux.dev
Reported-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Link: https://lore.kernel.org/r/20220914210750.423048-1-nhuck@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/ieee80211/ieee80211.h

@@ -2178,7 +2178,7 @@ int ieee80211_set_encryption(struct ieee80211_device *ieee);
 int ieee80211_encrypt_fragment(struct ieee80211_device *ieee,
 			       struct sk_buff *frag, int hdr_len);
 
-int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev);
+netdev_tx_t ieee80211_xmit(struct sk_buff *skb, struct net_device *dev);
 void ieee80211_txb_free(struct ieee80211_txb *txb);
 
 

drivers/staging/rtl8192u/ieee80211/ieee80211_tx.c

@@ -526,7 +526,7 @@ static void ieee80211_query_seqnum(struct ieee80211_device *ieee,
 	}
 }
 
-int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
+netdev_tx_t ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ieee80211_device *ieee = netdev_priv(dev);
 	struct ieee80211_txb *txb = NULL;
@@ -822,13 +822,13 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 			if ((*ieee->hard_start_xmit)(txb, dev) == 0) {
 				stats->tx_packets++;
 				stats->tx_bytes += __le16_to_cpu(txb->payload_size);
-				return 0;
+				return NETDEV_TX_OK;
 			}
 			ieee80211_txb_free(txb);
 		}
 	}
 
-	return 0;
+	return NETDEV_TX_OK;
 
  failed:
 	spin_unlock_irqrestore(&ieee->lock, flags);