This method allows you to convert an absolute symlink into a
relative one.
(From OE-Core rev: 71062c1e0fb45a4b4e58ea5d217706aa2b402d88)
Signed-off-by: Scott Garman <scott.a.garman@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>