scsi: qla2xxx: Fix improper freeing of purex item

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix improper freeing of purex item In qla2xxx_process_purls_iocb(), an item is allocated via qla27xx_copy_multiple_pkt(), which internally calls qla24xx_alloc_purex_item(). The qla24xx_alloc_purex_item() function may return a pre-allocated item from a per-adapter pool for small allocations, instead of dynamically allocating memory with kzalloc(). An error handling path in qla2xxx_process_purls_iocb() incorrectly uses kfree() to release the item. If the item was from the pre-allocated pool, calling kfree() on it is a bug that can lead to memory corruption. Fix this by using the correct deallocation function, qla24xx_free_purex_item(), which properly handles both dynamically allocated and pre-allocated items.