scsi hotplug: Set DriveInfo member bus correctly

drive_init() picks the first free bus and unit number, unless the user
specifies them.

This isn't a good fit for the drive_add monitor command, because there
we specify the controller by PCI address instead of using bus number
set by drive_init().

scsi_hot_add() takes care to replace the unit number set by
drive_init() by the real one, but it neglects to replace the bus
number.  Thus, bus/unit in DriveInfo may be bogus.  Affects
drive_get() and drive_get_max_bus().  I'm not aware of anything bad
happening because of that; looks like by the time we're hot-plugging,
the two functions aren't used anymore.  Fix it anyway.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

hw/pci-hotplug.c

@@ -90,6 +90,7 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
      * specified).
      */
     dinfo->unit = qemu_opt_get_number(dinfo->opts, "unit", -1);
+    dinfo->bus = scsibus->busnr;
     scsidev = scsi_bus_legacy_add_drive(scsibus, dinfo->bdrv, dinfo->unit, false);
     if (!scsidev) {
         return -1;