binman: Correct coverage gap in control

Add a pragma to deal with the code-coverage gap which drops binman down to
90% coverage.

Fixes: de65b122a2 (tools: Fall back to importlib_resources on Python 3.6)

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/control.py

@@ -9,7 +9,7 @@ from collections import OrderedDict
 import glob
 try:
     import importlib.resources
-except ImportError:
+except ImportError:  # pragma: no cover
     # for Python 3.6
     import importlib_resources
 import os