scsi: hisi_sas: Fix tag freeing for reserved tags

The reserved tags were put in the lower region of the tagset in commit
f7d190a9 ("scsi: hisi_sas: Put reserved tags in lower region of
tagset"). However, only the allocate function was changed, freeing was not
handled. This resulted in a failure to boot:

[   33.467345] hisi_sas_v3_hw 0000:b4:02.0: task exec: failed[-132]!
[   33.473413] sas: Executing internal abort failed 5000000000000603 (-132)
[   33.480088] hisi_sas_v3_hw 0000:b4:02.0: I_T nexus reset: internal abort (-132)
[   33.657336] hisi_sas_v3_hw 0000:b4:02.0: task exec: failed[-132]!
[   33.663403] ata7.00: failed to IDENTIFY (I/O error, err_mask=0x40)
[   35.787344] hisi_sas_v3_hw 0000:b4:04.0: task exec: failed[-132]!
[   35.793411] sas: Executing internal abort failed 5000000000000703 (-132)
[   35.800084] hisi_sas_v3_hw 0000:b4:04.0: I_T nexus reset: internal abort (-132)
[   35.977335] hisi_sas_v3_hw 0000:b4:04.0: task exec: failed[-132]!
[   35.983403] ata10.00: failed to IDENTIFY (I/O error, err_mask=0x40)
[   35.989643] ata10.00: revalidation failed (errno=-5)

Fixes: f7d190a9 ("scsi: hisi_sas: Put reserved tags in lower region of tagset")
Cc: John Garry <john.g.garry@oracle.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Acked-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>