scsi: qedi: Fix missing destroy_workqueue() on error in __qedi_probe

scsi: qedi: Fix missing destroy_workqueue() on error in __qedi_probe

Add the missing destroy_workqueue() before return from __qedi_probe in the
error handling case when fails to create workqueue qedi->offload_thread.

Link: https://lore.kernel.org/r/20201109091518.55941-1-miaoqinglang@huawei.com
Fixes: ace7f46ba5fd ("scsi: qedi: Add QLogic FastLinQ offload iSCSI driver framework.")
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>