Use pv instead of rd this make the function more generic and
avoid copy recipe data.
(From OE-Core rev: c1c3c9a4fbaf01a905f79b0970f98ccb221a3935)
Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>