scsi: lpfc: Fix lpfc_io_buf resource leak in lpfc_get_scsi_buf_s4 error path

If a call to lpfc_get_cmd_rsp_buf_per_hdwq returns NULL (memory allocation
failure), a previously allocated lpfc_io_buf resource is leaked.

Fix by releasing the lpfc_io_buf resource in the failure path.

Fixes: d79c9e9d ("scsi: lpfc: Support dynamic unbounded SGL lists on G7 hardware.")
Cc: <stable@vger.kernel.org> # v5.4+
Link: https://lore.kernel.org/r/20200128002312.16346-3-jsmart2021@gmail.comSigned-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_scsi.c

@@ -671,8 +671,10 @@ lpfc_get_scsi_buf_s4(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp,
 	lpfc_cmd->prot_data_type = 0;
 #endif
 	tmp = lpfc_get_cmd_rsp_buf_per_hdwq(phba, lpfc_cmd);
-	if (!tmp)
+	if (!tmp) {
+		lpfc_release_io_buf(phba, lpfc_cmd, lpfc_cmd->hdwq);
 		return NULL;
+	}
 
 	lpfc_cmd->fcp_cmnd = tmp->fcp_cmnd;
 	lpfc_cmd->fcp_rsp = tmp->fcp_rsp;