yocto-check-layer: check for duplicate layers when finding layers
detect_layers() is very greedy and if it recurses into poky or bitbake
it will find the test suite layers, such as
bitbake/lib/layerindexlib/tests/testdata/layer4. This is a dummy layer
which claims to be openembedded-layer, so if the real openembedded-layer
is a dependency then layer4 may be used instead, which will cause
errors: initially because it's only compatible with Sumo, but later
because it doesn't contain any recipes.
Add a check that the set of layers we've found doesn't contain any
duplicate collection names with different patterns, and abort if that is
the case as the test will be non-deterministic.
Signed-off-by: Ross Burton <ross.burton@arm.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
