hw: Propagate errors through qdev_prop_set_drive()

hw: Propagate errors through qdev_prop_set_drive()

Three kinds of callers:

1. On failure, report the error and abort

   Passing &error_abort does the job.  No functional change.

2. On failure, report the error and exit()

   This is qdev_prop_set_drive_nofail().  Error reporting moves from
   qdev_prop_set_drive() to its caller.  Because hiding away the error
   in the monitor right before exit() isn't helpful, replace
   qerror_report_err() by error_report_err().  Shouldn't make a
   difference, because qdev_prop_set_drive_nofail() should never be
   used in QMP context.

3. On failure, report the error and recover

   This is usb_msd_init() and scsi_bus_legacy_add_drive().  Error
   reporting and freeing the error object moves from
   qdev_prop_set_drive() to its callers.

   Because usb_msd_init() can't run in QMP context, replace
   qerror_report_err() by error_report_err() there.

   No functional change.

   scsi_bus_legacy_add_drive() calling qerror_report_err() is of
   course inappropriate, but this commit merely makes it more obvious.
   The next one will clean it up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-Id: <1425925048-15482-3-git-send-email-armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>