- fixed bug in ldlm_cancel_lru_local(). It should cancel locks according to...

- fixed bug in ldlm_cancel_lru_local(). It should cancel locks according to SLV only in the case of passed zero @count. If @count is not zero - cancel requested number of locks regardless SLV. Found by failure of sanityN test_20;
- raise error and return -EINVAL if ldlm_cancel_lru() did not cancel requested number of locks in case of sync cancel if lru resize is supported.