scsi: scsi_debug: Fix memleak in scsi_debug_init()

scsi: scsi_debug: Fix memleak in scsi_debug_init()

When sdeb_zbc_model does not match BLK_ZONED_NONE, BLK_ZONED_HA or
BLK_ZONED_HM, we should free sdebug_q_arr to prevent memleak. Also there is
no need to execute sdebug_erase_store() on failure of sdeb_zbc_model_str().

Link: https://lore.kernel.org/r/20201226061503.20050-1-dinghao.liu@zju.edu.cn
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>