qemu.test: virtio_storage_in_use, the drive format should be same between...

qemu.test: virtio_storage_in_use, the drive format should be same between system disk and data disk.
Signed-off-by: NXueqiang Wei <xuwei@redhat.com>

qemu/tests/cfg/virtio_storage_in_use.cfg

@@ -50,12 +50,14 @@
             remove_image_stg = yes
     variants:
         - with_block:
+            only virtio_blk
             driver_name = viostor
             drive_format = virtio
             iozone_cmd = "WIN_UTILS:\Iozone\iozone.exe -azR -r 64k -n 1G -g 2G -M -i 0 -i 1 -b iozone.xls -f ${disk_letter}:\testfile"
             iozone_timeout = 7200
             wait_bg_time = 180
         - with_vioscsi:
+            only virtio_scsi
             driver_name = vioscsi
             drive_format = scsi-hd
             iozone_cmd = "WIN_UTILS:\Iozone\iozone.exe -azR -r 64k -n 1G -g 2G -M -i 0 -i 1 -b iozone.xls -f ${disk_letter}:\testfile"