Display relative hotness with two decimal digits after the decimal point

I've seen cases where tiny inlined functions have such a high execution count
that most everything would show up with a relative of hotness of 0%.  Since
the inlined functions effectively disappear you need to tune in the lower
range, thus we need more precision.

llvm-svn: 314537

tools/opt-viewer/optrecord.py

@@ -179,7 +179,7 @@ class Remark(yaml.YAMLObject):
     @property
     def RelativeHotness(self):
         if self.max_hotness:
-            return "{}%".format(int(round(self.Hotness * 100 / self.max_hotness)))
+            return "{0:.2f}%".format(self.Hotness * 100. / self.max_hotness)
         else:
             return ''