fix(metrics): incorrect FP rate (#10300) (#10404)

Author: lmatz

docker/dashboards/risingwave-dev-dashboard.json

@@ -6,13 +6,13 @@ Share an easy-to-use profiler and flamegraph tool: https://github.com/koute/not-
 Record samples:
 
 ```shell
-nperf record -p `pidof compute-node` -o perf.data`
+nperf record -p `pidof compute-node` -o perf.data
 ```
 
 Generate flamegraph: 
 
 ```shell
-nperf flamegraph perf.data > perf.svg
+nperf flamegraph --merge-threads perf.data > perf.svg
 ```
 
 ## Profiling remote compute nodes

docs/cpu-profiling.md

@@ -1807,7 +1807,7 @@ def section_hummock(panels):
             "False-Positive / Positive",
             [
                 panels.target(
-                    f"1 - (((sum(rate({table_metric('state_store_read_req_positive_but_non_exist_counts')}[$__rate_interval])) by (job,instance,table_id,type))) / (sum(rate({table_metric('state_store_read_req_bloom_filter_positive_counts')}[$__rate_interval])) by (job,instance,table_id,type)))",
+                    f"(((sum(rate({table_metric('state_store_read_req_positive_but_non_exist_counts')}[$__rate_interval])) by (job,instance,table_id,type))) / (sum(rate({table_metric('state_store_read_req_bloom_filter_positive_counts')}[$__rate_interval])) by (job,instance,table_id,type)))",
                     "read req bloom filter false positive rate - {{table_id}} - {{type}} @ {{job}} @ {{instance}}",
                 ),
             ],