re-raise the original Exception instead of raising a new one

this preserves the error traceback and makes debugging easier

Change-Id: Ia513ac009b81d35e3df11939771aa29e40700c08

jenkins_jobs/builder.py

@@ -146,7 +146,7 @@ class JenkinsManager(object):
                                  'version': '',
                                  'longName': ''}]
             else:
-                raise e
+                raise
         logger.debug("Jenkins Plugin Info {0}".format(pformat(plugins_list)))
 
         return plugins_list

jenkins_jobs/cache.py

@@ -88,7 +88,7 @@ class JobCache(object):
                 # same time and that the other instance created the directory
                 # after we made the check, in which case there is no error
                 if ose.errno != errno.EEXIST:
-                    raise ose
+                    raise
         return path
 
     def set(self, job, md5):

tests/cmd/subcommands/test_test.py

@@ -363,8 +363,8 @@ class TestTestsMultiPath(CmdTestsBase):
     def check_dirs_match(self, expected_dir):
         try:
             self.assertThat(self.output_dir, MatchesDir(expected_dir))
-        except testtools.matchers.MismatchError as e:
-            raise e
+        except testtools.matchers.MismatchError:
+            raise
         else:
             shutil.rmtree(self.output_dir)