cros_ec_dev: Fix device path buffer

The buffer which stores the path of the CrOS EC device was
re-factored improperly when non-EC device support was added,
causing a buffer overflow which was exposed when flashrom
is compiled using clang.

BUG=chrome-os-partner:57950
BRANCH=none
TEST="flashrom -p ec -w ec.bin" no longer crashes when flashrom is
built using clang

Change-Id: I42c04f2fdecf8e6d595703e45d90f6ba7ede3721
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/390379
Reviewed-by: Gwendal Grignou <gwendal@google.com>
1 file changed