[PATCH v2 04/14] patman: Drop Python 2 StringIO code

[sjg at google.com]

We can rely on Python 3 now, so drop the workaround for importing
StringIO.

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

Changes in v2: None

 tools/patman/func_test.py | 5 +----
 tools/patman/settings.py  | 5 +----
 tools/patman/test_util.py | 5 +----
 3 files changed, 3 insertions(+), 12 deletions(-)

Applied to u-boot-dm, thanks!