[PATCH 13/20] patman: Correct some pylint and asyncio issues

[Simon Glass]

Correct some pylint warnings in this file. Make use of the existing
asyncio event loop, instead of creating a new one, since this also
destroys it afterwards, making it unavailable for tests which want to
share an event loop. Use tools.write_file() to avoid a warning about
encoding.

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

 tools/patman/func_test.py | 51 ++++++++++++++++++++-------------------
 1 file changed, 26 insertions(+), 25 deletions(-)

Applied to sjg/master, thanks!