libcmds: create directory before open in case it is not there

This could happen if you use kas to checkout repos that do not contain
the directory. i.e. repos that are not actually bb layers

Signed-off-by: Henning Schild <henning.schild@siemens.com>

kas/libcmds.py

@@ -169,6 +169,8 @@ class WriteConfig(Command):
     def execute(self, config):
         def _write_bblayers_conf(config):
             filename = config.build_dir + '/conf/bblayers.conf'
+            if not os.path.isdir(os.path.dirname(filename)):
+                os.makedirs(os.path.dirname(filename))
             with open(filename, 'w') as fds:
                 fds.write(config.get_bblayers_conf_header())
                 fds.write('BBLAYERS ?= " \\\n    ')