recipetool: create: add trailing newlines

recipetool: create: add trailing newlines

create_recipe() function relies on oe.recipeutils.patch_recipe_lines()
which relies on bb.utils.edit_metadata(). edit_metada expect lines to
have trailing newlines, so add it to each lines before calling
patch_recipe_lines, otherwise edit_metadata will not be able to squash
blank line if there are two consecutive blanks after a removal

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