debugd: log_tool: Change group to kDebugfsGroup to obtain EC panicinfo

/sys/kernel/debug is only accessible by user in debugfs-access group,
even though the panicinfo file itself is world-readable.

BUG=chromium:527904
BUG=chromium:643031
TEST=File feedback, panicinfo is present

Change-Id: I98fff3a511b944639bab10f78db8581923c4a32e
Previous-Reviewed-on: https://chromium-review.googlesource.com/379678
(cherry picked from commit f59e261a0cfd99b36a6772dcc266b915ad3baa26)
Reviewed-on: https://chromium-review.googlesource.com/381755
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
1 file changed