tools/crimson/crimson_stress_tool: fix bugs

fix single core parameter doesn't work.

fix node process will not be killed in the lateset ceph master.

fix ReactorUtilizationCollectorThread will not run in the target core.

some parameter changes.

Signed-off-by: Xinyu Huang <xinyu.huang@intel.com>

Author: aisakaki

tools/crimson/README.rst

@@ -105,8 +105,8 @@ Example:
         --client-list 4 8 --thread-list 2 4 6 --taskset 16-31 --time 300 \ 
         --rand-write 0.75 \
         --rand-read 0.25 \ 
-        --reactor-utilization True \
-        --perf True \
+        --reactor-utilization \
+        --perf \
         --scenario crimson-seastore
 
 The tool will run rados bench write and read test case with the combination