test: add command to 'Lab failure' timeout message

When a timeout occurs while executing a command a 'Lab failure' message is
written and testing is stopped. The user is left in the dark about the
failure cause.

    ! _pytest.outcomes.Exit: Lab failure: Marking connection bad - no other tests will run !

Add the word 'Timeout' and the executed command to the message.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

test/py/u_boot_console_base.py

@@ -342,8 +342,8 @@ class ConsoleBase(object):
             # indentation.
             return self.p.before.strip('\r\n')
         except Timeout as exc:
-            handle_exception(self.config, self, self.log, exc, 'Lab failure',
-                             True)
+            handle_exception(self.config, self, self.log, exc,
+                             f"Lab failure: Timeout executing '{cmd}'", True)
             raise
         except BootFail as exc:
             handle_exception(self.config, self, self.log, exc, 'Boot fail',