Bluetooth: btintel_pcie: validate packet_len before skb_put_data

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btintel_pcie: validate packet_len before skb_put_data btintel_pcie_submit_rx_work() reads packet_len from rfh_hdr without checking if it exceeds the RX buffer size. An oversized packet_len can lead to an out-of-bounds read in skb_put_data(). Validate packet_len to ensure it is non-zero and does not exceed BTINTEL_PCIE_BUFFER_SIZE - sizeof(*rfh_hdr), logging an error when invalid. This issue was reported by Claude Mythos. It can be simulated either by using customized firmware configured to return an invalid packet_len or by modifying rfh_hdr->packet_len in the driver before calling btintel_pcie_submit_rx_work().