By Lawrence Delevingne NEW YORK (Reuters) - David Einhorn's Greenlight Capital renewed criticism of Elon Musk and his Tesla Inc, saying the electric car company again appeared to be on the "brink" of failure, according to a letter sent to clients of the hedge fund on Friday. The letter cited a lack of demand, "desperate" price cuts, layoffs, "closing-and-then-not-closing" stores, closing service centers, slashing capital expenditures, rushed product announcements and "a new effort to distract investors from the demand problem with hyperbole over TSLA's autonomous driving capabilities."