eSDK.py: avoid error in tearDownClass due to race condistion

When removing the temporary directory, it's possible that bitbake.lock
file is removed by bitbake during the cleanup. And this leads to the
following error.

  FileNotFoundError: [Errno 2] No such file or directory: 'bitbake.lock'

So add a check to remove this file before cleaning up the temporary
directory.

(From OE-Core rev: 984f56b37bd0014e5bf9509fc8ed181973e61773)

(From OE-Core rev: 6a5cce862f1e950439dc8ee1d84a10397a7fac4f)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/eSDK.py

@@ -2,6 +2,7 @@ import tempfile
 import shutil
 import os
 import glob
+import time
 from oeqa.core.decorator.oeid import OETestID
 from oeqa.selftest.case import OESelftestTestCase
 from oeqa.utils.commands import runCmd, bitbake, get_bb_var, get_bb_vars
@@ -95,6 +96,11 @@ SSTATE_MIRRORS =  "file://.* file://%s/PATH"
 
     @classmethod
     def tearDownClass(cls):
+        for i in range(0, 10):
+            if os.path.exists(os.path.join(cls.tmpdir_eSDKQA, 'bitbake.lock')):
+                time.sleep(1)
+            else:
+                break
         cls.tmpdirobj.cleanup()
         super().tearDownClass()