scsi: qla2xxx: Remove unused struct 'scsi_dif_tuple'

'scsi_dif_tuple' is unused since commit 8cb2049c ("[SCSI] qla2xxx: T10
DIF - Handle uninitalized sectors.").

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20240528215640.91771-1-linux@treblig.orgReviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_isr.c

@@ -3014,12 +3014,6 @@ qla2x00_handle_sense(srb_t *sp, uint8_t *sense_data, uint32_t par_sense_len,
 	}
 }
 
-struct scsi_dif_tuple {
-	__be16 guard;       /* Checksum */
-	__be16 app_tag;         /* APPL identifier */
-	__be32 ref_tag;         /* Target LBA or indirect LBA */
-};
-
 /*
  * Checks the guard or meta-data for the type of error
  * detected by the HBA. In case of errors, we set the