scsi: scsi_debug: Rework page code error handling

Instead of tracking whether or not the page code is valid in a boolean
variable, jump to error handling code if an unsupported page code is
encountered.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-15-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: bvanassche

drivers/scsi/scsi_debug.c

@@ -2644,7 +2644,7 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 	unsigned char *ap;
 	unsigned char arr[SDEBUG_MAX_MSENSE_SZ];
 	unsigned char *cmd = scp->cmnd;
-	bool dbd, llbaa, msense_6, is_disk, is_zbc, bad_pcode;
+	bool dbd, llbaa, msense_6, is_disk, is_zbc;
 
 	dbd = !!(cmd[1] & 0x8);		/* disable block descriptors */
 	pcontrol = (cmd[2] & 0xc0) >> 6;
@@ -2708,7 +2708,6 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
 		return check_condition_result;
 	}
-	bad_pcode = false;
 
 	switch (pcode) {
 	case 0x1:	/* Read-Write error recovery page, direct access */
@@ -2723,15 +2722,17 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		if (is_disk) {
 			len = resp_format_pg(ap, pcontrol, target);
 			offset += len;
-		} else
-			bad_pcode = true;
+		} else {
+			goto bad_pcode;
+		}
 		break;
 	case 0x8:	/* Caching page, direct access */
 		if (is_disk || is_zbc) {
 			len = resp_caching_pg(ap, pcontrol, target);
 			offset += len;
-		} else
-			bad_pcode = true;
+		} else {
+			goto bad_pcode;
+		}
 		break;
 	case 0xa:	/* Control Mode page, all devices */
 		len = resp_ctrl_m_pg(ap, pcontrol, target);
@@ -2784,18 +2785,17 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		}
 		break;
 	default:
-		bad_pcode = true;
-		break;
-	}
-	if (bad_pcode) {
-		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
-		return check_condition_result;
+		goto bad_pcode;
 	}
 	if (msense_6)
 		arr[0] = offset - 1;
 	else
 		put_unaligned_be16((offset - 2), arr + 0);
 	return fill_from_dev_buffer(scp, arr, min_t(u32, alloc_len, offset));
+
+bad_pcode:
+	mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
+	return check_condition_result;
 }
 
 #define SDEBUG_MAX_MSELECT_SZ 512