[SCSI] More USB deadlock fixes

This patch fixes a corner case in the previous USB Deadlock fix patch (12023e7
[SCSI] Fix USB deadlock caused by SCSI error handling).

The scenario is abort command, set flag, abort completes, send TUR, TUR
doesn't return, so we now try to abort the TUR, but scsi_abort_eh_cmnd()
will skip the abort because the flag is set and move straight to reset.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>