stasis_channels.c: Eliminate another overuse of RAII_VAR().

git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@411636 f38db490-d61c-443f-a65b-d21fe96a405b
res_parking: Minor tweaks.

* Use ast_bridge_channel_lock()/ast_bridge_channel_unlock() instead of
ao2_lock()/ao2_unlock() for struct ast_bridge_channel variables.

* Use ast_copy_string() instead of inlining it.

* Remove an already done TODO comment.

* Some whitespace tweaks.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@411638 f38db490-d61c-443f-a65b-d21fe96a405b