cros_ec: use open() instead of file_open() wrapper

file_open() does a lot of helpful things which include creating a
file that doesn't exist if FILE_WRITE mode is set. This can have
unfortunate side-effects, though, such as when attempting to write
to a device node in /dev which doesn't exist and leaving behind
a regular file.

BUG=chromium:314765
BRANCH=none
TEST=tested on Snow with 3.4 kernel, no longer see /dev/cros_ec
being created.

Change-Id: I46a3d9fc5397b75a993fa96043fde6913cf97498
Reviewed-on: https://chromium-review.googlesource.com/175967
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/176055
Reviewed-by: David Hendricks <dhendrix@chromium.org>
1 file changed