esp: correctly fill bus id with requested lun

This bug showed up after 1455084ea2c48abf23c4e4e15e378ee43457f381, and
may be seen only on operating systems *not* using DMA to give commands
to SCSI adapter.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

hw/esp.c

diff --git a/hw/esp.c b/hw/esp.c
index 6d3f5d2..8e95672 100644
--- a/hw/esp.c
+++ b/hw/esp.c
@@ -211,7 +211,7 @@
     } else {
         dmalen = s->ti_size;
         memcpy(buf, s->ti_buf, dmalen);
-        buf[0] = 0;
+        buf[0] = buf[2] >> 5;
     }
     DPRINTF("get_cmd: len %d target %d\n", dmalen, target);