[PATCH 2 of 9 RFC] statprof: fix flake8 warnings

[Gregory Szorc]

# HG changeset patch
# User Gregory Szorc <gregory.szorc at gmail.com>
# Date 1471227212 25200
#      Sun Aug 14 19:13:32 2016 -0700
# Node ID 3f37aba5e38717c7373101e7c868d13f6d809574
# Parent  d9790aec4f500ab47c550b033f84fc090e537fc3
statprof: fix flake8 warnings

My local flake8 hook informed me of these warnings in the upstream
code. Fix them.

diff --git a/mercurial/statprof.py b/mercurial/statprof.py
--- a/mercurial/statprof.py
+++ b/mercurial/statprof.py
@@ -99,21 +99,20 @@ Because signals only get delivered to th
 statprof only profiles the main thread. However because the time
 reporting function uses per-process timers, the results can be
 significantly off if other threads' work patterns are not similar to the
 main thread's work patterns.
 """
 # no-check-code
 from __future__ import division
 
-import inspect, json, os, signal, tempfile, sys, getopt, threading, traceback
+import inspect, json, os, signal, tempfile, sys, getopt, threading
 import time
 from collections import defaultdict
 from contextlib import contextmanager
-from subprocess import call
 
 __all__ = ['start', 'stop', 'reset', 'display', 'profile']
 
 skips = set(["util.py:check", "extensions.py:closure",
              "color.py:colorcmd", "dispatch.py:checkargs",
              "dispatch.py:<lambda>", "dispatch.py:_runcatch",
              "dispatch.py:_dispatch", "dispatch.py:_runcommand",
              "pager.py:pagecmd", "dispatch.py:run",
@@ -321,17 +320,17 @@ def save_data(path=None):
         for sample in state.samples:
             time = str(sample.time)
             stack = sample.stack
             sites = ['\1'.join([s.path, str(s.lineno), s.function])
                      for s in stack]
             file.write(time + '\0' + '\0'.join(sites) + '\n')
 
         file.close()
-    except (IOError, OSError) as ex:
+    except (IOError, OSError):
         # The home directory probably didn't exist, or wasn't writable. Oh well.
         pass
 
 def load_data(path=None):
     path = path or (os.environ['HOME'] + '/statprof.data')
     lines = open(path, 'r').read().splitlines()
 
     state.accumulated_time = float(lines[0])