cxgb4/ch_ktls: disable softirqs around tid_list erases

In the Linux kernel, the following vulnerability has been resolved: cxgb4/ch_ktls: disable softirqs around tid_list erases chcr_ktls_cpl_act_open_rpl() inserts into tid_list from the receive path using xa_insert_bh(). The array is shared by the adapter's connections and initialized with XA_FLAGS_LOCK_BH. However, chcr_ktls_dev_del() and the chcr_ktls_dev_add() error path use xa_erase(), which takes the XArray lock without disabling softirqs. When cleanup runs with softirqs enabled, a receive softirq for another connection on the same CPU can interrupt the erase and spin on the lock held by the interrupted task. Use xa_erase_bh() at both sites to match the insertion path.