CliClient print memtable threshold in incorrect order

as a continuation from #2839 looks like it was incorrectly merged into 0.8 as well, hence affecting > 0.8.2.

for trunk, this is also changed (time is taken out). So I guess format wise, we would stick with the fixed format in 0.7.7 per #2839 , which is:

sessionState.out.printf("      Memtable thresholds: %s/%s/%s (millions of ops/minutes/MB)%n",
    cf_def.memtable_operations_in_millions, cf_def.memtable_flush_after_mins, cf_def.memtable_throughput_in_mb);