recipetool: create: fix picking up false npm package directories
It is possible for a Node.js module to have node_modules subdirectories
that contain no package.json file (e.g. iotivity-node has such a
directory). It appears these should simply be ignored, or else with the
way the current code works we will get errors later.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
