net/packet: Remove redundant assignment to ret

Variable ret is set to '0' or '-EBUSY', but this value is never read
as it is not used later on, hence it is a redundant assignment and
can be removed.

Clean up the following clang-analyzer warning:

net/packet/af_packet.c:3936:4: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

net/packet/af_packet.c:3933:4: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

No functional change.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet/af_packet.c

@@ -3923,12 +3923,9 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
 			return -EFAULT;
 
 		lock_sock(sk);
-		if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
-			ret = -EBUSY;
-		} else {
+		if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec)
 			po->tp_tx_has_off = !!val;
-			ret = 0;
-		}
+
 		release_sock(sk);
 		return 0;
 	}