scsi: core: Add missing scsi_device_put() in scsi_host_block()

scsi: core: Add missing scsi_device_put() in scsi_host_block()

The scsi_host_block() case was missing in commit 4dea170f4fb2 ("scsi: core:
Fix incorrect usage of shost_for_each_device").

Link: https://lore.kernel.org/r/20200717090921.29243-1-yebin10@huawei.com
Fixes: 2bb955840c1d ("scsi: core: add scsi_host_(block,unblock) helper function")
Fixes: 4dea170f4fb2 ("scsi: core: Fix incorrect usage of shost_for_each_device")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>