scsi: pm8001: Fix memleak in pm8001_exec_internal_task_abort

When pm8001_tag_alloc() fails, task should be freed just like it is done in
the subsequent error paths.

Link: https://lore.kernel.org/r/20200823091453.4782-1-dinghao.liu@zju.edu.cn


Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>