Add -C to 'rbt patch' docs.
Add -C to 'rbt patch' docs.

Trivial addition to docs.

halvorlu/rbtools,datjwu/rbtools,davidt/rbtools,davidt/rbtools,datjwu/rbtools,haosdent/rbtools,reviewboard/rbtools,beol/rbtools,halvorlu/rbtools,beol/rbtools,haosdent/rbtools,datjwu/rbtools,haosdent/rbtools,beol/rbtools,davidt/rbtools,reviewboard/rbtools,reviewboard/rbtools,halvorlu/rbtools