st.st_blocks is always counted in 512 byte units. Do not
use st.st_blksize as multiplicator which may be larger.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1440067607-14547-1-git-send-email-pl@kamp.de
Signed-off-by: Jeff Cody <jcody@redhat.com>