scsi: fix fw path

The pre-1.0 firmware path for SCSI devices already included the LUN
using the suffix argument to add_boot_device_path.  I missed that when
making channel and LUN customizable.  Avoid that it is included twice, and
convert the colons to commas for consistency with other kinds of devices
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

hw/scsi-bus.c

@@ -1279,7 +1279,7 @@ static char *scsibus_get_fw_dev_path(DeviceState *dev)
     SCSIDevice *d = DO_UPCAST(SCSIDevice, qdev, dev);
     char path[100];
 
-    snprintf(path, sizeof(path), "%s@%d:%d:%d", qdev_fw_name(dev),
+    snprintf(path, sizeof(path), "%s@%d,%d,%d", qdev_fw_name(dev),
              d->channel, d->id, d->lun);
 
     return strdup(path);

hw/scsi-disk.c

@@ -1553,7 +1553,7 @@ static int scsi_initfn(SCSIDevice *dev)
     bdrv_set_buffer_alignment(s->qdev.conf.bs, s->qdev.blocksize);
 
     bdrv_iostatus_enable(s->qdev.conf.bs);
-    add_boot_device_path(s->qdev.conf.bootindex, &dev->qdev, ",0");
+    add_boot_device_path(s->qdev.conf.bootindex, &dev->qdev, NULL);
     return 0;
 }