devtool: drop S = WORKDIR workaround

devtool: drop S = WORKDIR workaround

Dropping support for S = WORKDIR allows to drop this ugly workaround.

With S = WORKDIR it was possible to refer to a file via oe-local-files
symlink or via direct file path. Ensuring the pseudo database is
consistent for both paths was extra complicated and required this bad
function. Really nice to drop it now!

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>