os_linux.cpp: linux_aacraid_device: Fix ioctl data count if dxfer_len == 0.
Return scsi sense data.  Together these allow the SMART STATUS command to
operate correctly.  Improve SRB status checks.
linux_ata_device: Fix very old bug in the error handling of
HDIO_DRIVE_TASKFILE.

git-svn-id: https://svn.code.sf.net/p/smartmontools/code/trunk/smartmontools@4003 4ea69e1a-61f1-4043-bf83-b5c94c648137