This gives us the needed context of the original ExpansionError, which is
invaluable when we have a chain of function calls in the expansion.
(Bitbake rev: c514b6fbea77ede1b7871b89592a33ed39b1d71c)
Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>