SUNRPC: remove dead variable 'rpciod_running'

rpciod_running is not used at all, but due to the way DECLARE_MUTEX_LOCKED
works we don't get a warning for it.


Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>