Direct plugin logs through vault's logger

[calvn]

Plugin logs now go through core's logger.

...
2017/08/10 17:20:10.348312 [INFO ] core: post-unseal setup complete
2017/08/10 17:20:14.839109 [DEBUG] plugin: starting plugin: path=/Users/cleung/code/tmp/vault_plugins/mock-plugin args=[/Users/cleung/code/tmp/vault_plugins/mock-plugin]
2017/08/10 17:20:14.841726 [DEBUG] plugin: waiting for RPC address: path=/Users/cleung/code/tmp/vault_plugins/mock-plugin
2017/08/10 17:20:14.888501 [DEBUG] plugin.mock-plugin: plugin address: address=/var/folders/1x/c_x5s2h90mzdyx4bzz3_dsx80000gn/T/plugin748882765 network=unix
2017/08/10 17:20:14.987489 [INFO ] core: successful mount: path=mock/ type=plugin
^C==> Vault shutdown triggered
2017/08/10 17:20:19.602519 [DEBUG] core: marked as sealed
2017/08/10 17:20:19.602589 [TRACE] core: clearing forwarding clients
2017/08/10 17:20:19.602610 [TRACE] core: done clearing forwarding clients
2017/08/10 17:20:19.602627 [INFO ] core: pre-seal teardown starting
2017/08/10 17:20:19.602643 [INFO ] core: cluster listeners not running
2017/08/10 17:20:19.602679 [INFO ] rollback: stopping rollback manager
2017/08/10 17:20:19.604545 [DEBUG] plugin.mock-plugin: plugin received interrupt signal, ignoring: count=1
2017/08/10 17:20:19.608004 [DEBUG] plugin: plugin process exited: path=/Users/cleung/code/tmp/vault_plugins/mock-plugin
2017/08/10 17:20:19.608212 [INFO ] core: pre-seal teardown complete
2017/08/10 17:20:19.608254 [DEBUG] core: sealing barrier
2017/08/10 17:20:19.608275 [INFO ] core: vault is sealed

[jefferai]

Was this actually necessary? The pointer access should be transparent I thought.

[calvn]

I went with this since hclog was doing the same, unless it applies differently in that case: https://github.com/hashicorp/go-hclog/blob/master/int.go#L346

[jefferai]

Pretty sure it's unnecessary there too. But it doesn't matter either way, really.