Kernel: Release packet buffer in TCPSocket::send_tcp_packet

Previously we wouldn't release the buffer back to the network adapter
in all cases. While this didn't leak the buffer it would cause the
buffer to not be reused for other packets.

Kernel/Net/TCPSocket.cpp

@@ -220,8 +220,10 @@ KResult TCPSocket::send_tcp_packet(u16 flags, const UserOrKernelBuffer* payload,
         tcp_packet.set_ack_number(m_ack_number);
     }
 
-    if (payload && !payload->read(tcp_packet.payload(), payload_size))
+    if (payload && !payload->read(tcp_packet.payload(), payload_size)) {
+        routing_decision.adapter->release_packet_buffer(*packet);
         return EFAULT;
+    }
 
     if (flags & TCPFlags::SYN) {
         ++m_sequence_number;
@@ -247,6 +249,8 @@ KResult TCPSocket::send_tcp_packet(u16 flags, const UserOrKernelBuffer* payload,
         m_not_acked.append({ m_sequence_number, move(packet), ipv4_payload_offset, *routing_decision.adapter });
         m_not_acked_size += payload_size;
         enqueue_for_retransmit();
+    } else {
+        routing_decision.adapter->release_packet_buffer(*packet);
     }
 
     return KSuccess;