In the various channel request mini-coroutines, replace
crWaitUntilV(pktin) with plain crReturnV, because those coroutines can
be called back either with a response packet from the channel request
_or_ with NULL by ssh_free meaning 'please just clean yourself up'.


git-svn-id: svn://svn.tartarus.org/sgt/putty@9927 cda61777-01e9-0310-a592-d414129be87e