Bluetooth: Fix passing NULL to PTR_ERR

Passing NULL to PTR_ERR will result in 0 (success), also since the likes of
bt_skb_sendmsg does never return NULL it is safe to replace the instances of
IS_ERR_OR_NULL with IS_ERR when checking its return.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/bluetooth.h

@@ -496,7 +496,7 @@ static inline struct sk_buff *bt_skb_sendmmsg(struct sock *sk,
 		struct sk_buff *tmp;
 
 		tmp = bt_skb_sendmsg(sk, msg, len, mtu, headroom, tailroom);
-		if (IS_ERR_OR_NULL(tmp)) {
+		if (IS_ERR(tmp)) {
 			kfree_skb(skb);
 			return tmp;
 		}

net/bluetooth/rfcomm/sock.c

@@ -583,7 +583,7 @@ static int rfcomm_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 
 	skb = bt_skb_sendmmsg(sk, msg, len, d->mtu, RFCOMM_SKB_HEAD_RESERVE,
 			      RFCOMM_SKB_TAIL_RESERVE);
-	if (IS_ERR_OR_NULL(skb))
+	if (IS_ERR(skb))
 		return PTR_ERR(skb);
 
 	sent = rfcomm_dlc_send(d, skb);

net/bluetooth/sco.c

@@ -733,7 +733,7 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 		return -EOPNOTSUPP;
 
 	skb = bt_skb_sendmsg(sk, msg, len, len, 0, 0);
-	if (IS_ERR_OR_NULL(skb))
+	if (IS_ERR(skb))
 		return PTR_ERR(skb);
 
 	lock_sock(sk);