[LNT] Python 3 support: remove useless var-setting getter

Both the ComparisonResult constructor and the stddev_mean getter set
the readonly stddev_mean. While Python 2 accepts it, Python 3 throws
errors (cannot set attribute and infinite recursion respectively). Since
that attribute does not appear to be used anywhere, this commit removes
all this code.

Reviewers: cmatthews, hubert.reinterpretcast, kristof.beyls

Reviewed By: hubert.reinterpretcast

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D67882

llvm-svn: 374302

Author: Thomas Preud'homme

lnt/server/reporting/analysis.py

@@ -96,7 +96,6 @@ def __init__(self, aggregation_fn,
             self.stddev = None
             self.MAD = None
 
-        self.stddev_mean = None  # Only calculate this if needed.
         self.failed = cur_failed
         self.prev_failed = prev_failed
         self.samples = samples
@@ -105,14 +104,6 @@ def __init__(self, aggregation_fn,
         self.confidence_lv = confidence_lv
         self.bigger_is_better = bigger_is_better
 
-    @property
-    def stddev_mean(self):
-        """The mean around stddev for current sampples. Cached after first call.
-        """
-        if not self.stddev_mean:
-            self.stddev_mean = stats.mean(self.samples)
-        return self.stddev_mean
-
     def __repr__(self):
         """Print this ComparisonResult's constructor.