src,http_parser: remove KickNextTick call

Now that HTTPParser uses MakeCallback it is unnecessary to manually
process the nextTickQueue.

The KickNextTick function is now no longer needed so code has moved back
to node::MakeCallback to simplify implementation.

Include minor cleanup moving Environment::tick_info() call below the
early return to save an operation.

PR-URL: https://github.com/nodejs/node/pull/5756


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Andreas Madsen <amwebdk@gmail.com>