misc: fix error handling in punt_replicate

misc: fix error handling in punt_replicate

If vlib_buffer_clone (...) fails due to a buffer allocation error, update
*n_dispatched with the actual number of clones, not the requested
number of clones.

Punt_replicate(...) should not set *to_next[0] = bi0. The original
buffer is enqueued separately in punt_dispatch_node(...)

Type: fix

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I774ad8f8c1a0633de4cf8ae5530629201c229347
(cherry picked from commit 1adc7e78ad3eb7e800d0ce3ace56f53ab7aebffe)