rx: Remove rx_waitingForPacket

Commit f43c2f4412d670ce1131dc429cb43302352df3e4 introduced
rx_waitingForPacket.  Given its current usage, I can't see any
functionality.

It looks like this might have been the result of merging a renamed
rx_waitForPacket from another development branch?

Change-Id: I47fc7a2b25cbfcd59ea4ad1606b734bb9d4ceecc
Reviewed-on: http://gerrit.openafs.org/10981
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>