avocado.core.test: Fix SimpleTest

With the d6abdcd4 Test methods changed
but for SimpleTest the wrong method was chosed and only the test
execution is performed now, the post-process class is completelly
ignored. This changes the method to the correct one and adjusts
ExternalRunner to not run this postprocess.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

avocado/core/test.py

@@ -671,7 +671,7 @@ class SimpleTest(Test):
         self.log.info("Exit status: %s", result.exit_status)
         self.log.info("Duration: %s", result.duration)
 
-    def test(self):
+    def execute_cmd(self):
         """
         Run the executable, and log its detailed execution.
         """
@@ -688,8 +688,11 @@ class SimpleTest(Test):
             self._log_detailed_cmd_info(details.result)
             raise exceptions.TestFail(details)
 
-    def run(self, result=None):
-        super(SimpleTest, self).run(result)
+    def test(self):
+        """
+        Run the test and postprocess the results
+        """
+        self.execute_cmd()
         for line in open(self.logfile):
             if self.re_avocado_log.match(line):
                 raise exceptions.TestWarn("Test passed but there were warnings"
@@ -732,7 +735,7 @@ class ExternalRunnerTest(SimpleTest):
                                new_cwd)
                 os.chdir(new_cwd)
 
-            super(ExternalRunnerTest, self).test()
+            self.execute_cmd()
 
         finally:
             if new_cwd is not None: