binman: Re-enable concurrent tests

With the change to absolute imports the concurrent tests feature
unfortunately broke. Fix it.

We cannot easy add a warning, since the output messes up tests which check
the output.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/patman/test_util.py b/tools/patman/test_util.py
index 20dc1e4..4e26175 100644
--- a/tools/patman/test_util.py
+++ b/tools/patman/test_util.py
@@ -16,7 +16,8 @@
 
 use_concurrent = True
 try:
-    from concurrencytest import ConcurrentTestSuite, fork_for_tests
+    from concurrencytest.concurrencytest import ConcurrentTestSuite
+    from concurrencytest.concurrencytest import fork_for_tests
 except:
     use_concurrent = False
 
@@ -50,6 +51,7 @@
         glob_list = []
     glob_list += exclude_list
     glob_list += ['*libfdt.py', '*site-packages*', '*dist-packages*']
+    glob_list += ['*concurrencytest*']
     test_cmd = 'test' if 'binman' in prog or 'patman' in prog else '-t'
     prefix = ''
     if build_dir: