yocto-check-layer: Remove duplicated code

Nicolas Dechesne spotted there was duplicate code I had introduced with a
previous fix. Remove the second statement since the earlier one is correct
all that is needed.

(From OE-Core rev: f3e8d9f0e53e73de5498fccce81d049a88f6473b)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/yocto-check-layer

@@ -152,8 +152,6 @@ def main():
         logger.info("Setting up for %s(%s), %s" % (layer['name'], layer['type'],
             layer['path']))
 
-        shutil.copyfile(bblayersconf + '.backup', bblayersconf)
-
         missing_dependencies = not add_layer_dependencies(bblayersconf, layer, dep_layers, logger)
         if not missing_dependencies:
             for additional_layer in additional_layers: