Bug 841935: Use sys.executable to invoke b2g update scripts. r=jgriffin a=tef+

testing/marionette/update-smoketests/smoketest.py

@@ -135,7 +135,7 @@ class SmokeTestRunner(object):
         if not os.path.exists(partial_mar):
             build_gecko_mar = os.path.join(self.b2g.update_tools,
                                            'build-gecko-mar.py')
-            subprocess.check_call([build_gecko_mar,
+            subprocess.check_call([sys.executable, build_gecko_mar,
                                    '--from', start_data.complete_mar,
                                    '--to', finish_data.complete_mar,
                                    partial_mar])

testing/marionette/update-smoketests/stage-update.py

@@ -50,7 +50,7 @@ def stage_update(device, stage_dir):
     print 'Building flash zip for device %s, version %s, build %s...' % \
           (device, app_version, build_id)
 
-    subprocess.check_call([build_flash_fota,
+    subprocess.check_call([sys.executable, build_flash_fota,
         '--system-dir', os.path.join(target_out_dir, 'system'),
         '--system-fs-type', device_data.system_fs_type,
         '--system-location', device_data.system_location,