license_image.bbclass: Don't attempt to symlink to the same file
Sometimes (that is, in all my builds) the lic_manifest_dir and
lic_manifest_symlink_dir end up pointing to the same file, resulting
in an error like this:
Exception: FileExistsError: [Errno 17] File exists: '/.../tmp-glibc/deploy/licenses/my-image-tdkz15' -> '/.../tmp-glibc/deploy/licenses/my-image-tdkz15'
First check to see if this is the case before attempting to create
the link.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
