scsi: qla2xxx: Null out freed pointers in qla2x00_mem_alloc() error path

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Null out freed pointers in qla2x00_mem_alloc() error path When qla2x00_mem_alloc() fails, qla2x00_probe_one() jumps to probe_hw_failed and calls qla2x00_mem_free(). Several error labels in qla2x00_mem_alloc() freed adapter members (elsrej.c, purex_dma_pool, flt, sfp_data, loop_id_map, async_pd, sf_init_cb, ex_init_cb, npiv_info) but left the pointers dangling. qla2x00_mem_free() then freed them a second time. Worse, for the dma_pool members it issued dma_pool_free(ha->s_dma_pool, ...) after s_dma_pool had already been destroyed and set to NULL at fail_s_dma_pool, dereferencing a NULL pool. Clear each freed pointer (and its DMA handle) in the error labels so the subsequent qla2x00_mem_free() skips them.