scsi: iscsi_tcp: Drop target_alloc use

scsi: iscsi_tcp: Drop target_alloc use

For software iSCSI, we do a session per host so there is no need to set the
target's can_queue since it's the same as the host one. Setting it just
results in extra atomic checks in the main I/O path.

Link: https://lore.kernel.org/r/20220616224557.115234-6-michael.christie@oracle.com
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>