Added fall-through comments to several fall-throughs.

src/scsi/scsi_buslogic.c

@@ -1250,6 +1250,7 @@ BuslogicPCIWrite(int func, int addr, uint8_t val, void *p)
 
 	case 0x14:
 		val &= 0xe0;
+		/*FALLTHROUGH*/
 
 	case 0x15: case 0x16: case 0x17:
 		/* MMIO Base set. */

src/scsi/scsi_cdrom.c

@@ -1537,6 +1537,8 @@ scsi_cdrom_command(scsi_common_t *sc, uint8_t *cdb)
 		/* IMPORTANT: Convert the command to new read CD
 			      for pass through purposes. */
 		dev->current_cdb[0] = 0xbe;
+		/*FALLTHROUGH*/
+
 	case GPCMD_READ_6:
 	case GPCMD_READ_10:
 	case GPCMD_READ_12:

src/scsi/scsi_disk.c

@@ -613,6 +613,7 @@ scsi_disk_command(scsi_common_t *sc, uint8_t *cdb)
 			scsi_disk_invalid_field(dev);
 			return;
 		}
+		/*FALLTHROUGH*/
 	case GPCMD_SCSI_RESERVE:
 	case GPCMD_SCSI_RELEASE:
 	case GPCMD_TEST_UNIT_READY: