Fix bug in count_range.
Fix bug in count_range.

Reported by Takahiro YAMAMOTO.

stipple/cassandra_new,rightscale/cassandra,cassandra-rb/cassandra,stipple/cassandra_new,stipple/cassandra_new,stipple/cassandra_new,rightscale/cassandra,rightscale/cassandra,cassandra-rb/cassandra,cassandra-rb/cassandra,cassandra-rb/cassandra