Increase the precision of comparison (#346)

Author: k0kubun

run_benchmarks.rb

@@ -498,11 +498,11 @@ def run_benchmarks(ruby:, ruby_description:, categories:, name_filters:, out_pat
 end
 other_names.each do |name|
   table[0] += ["#{name} 1st itr"]
-  format   += ["%.2f"]
+  format   += ["%.3f"]
 end
 other_names.each do |name|
   table[0] += ["#{base_name}/#{name}"]
-  format   += ["%.2f"]
+  format   += ["%.3f"]
 end
 
 # Format the results table