ec: fix -Wuninitialized warning.
ec: fix -Wuninitialized warning.

BUG=chromium:488540
Signed-off-by: 8ca9e07d8da722742b3f5a8340e0afab8cf1248e@chromium.org
BRANCH=none
TEST=FEATURES="test" CC=x86_64-cros-linux-gnu-clang
     CXX=x86_64-cros-linux-gnu-clang++ emerge-falco chromeos-ec

Change-Id: If70f7de921a2e973c093a92f03fa0f1603ee0b08
Reviewed-on: https://chromium-review.googlesource.com/271476
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>
Reviewed-by: Yunlian Jiang <8ca9e07d8da722742b3f5a8340e0afab8cf1248e@chromium.org>
Reviewed-by: Sheng-liang Song <20a24593f82e573953076a0eeaf8f3cfb817a534@chromium.org>
Commit-Queue: Sheng-liang Song <20a24593f82e573953076a0eeaf8f3cfb817a534@chromium.org>
Tested-by: Sheng-liang Song <20a24593f82e573953076a0eeaf8f3cfb817a534@chromium.org>

fourier49/BZ_DEV_EC,fourier49/BZ_DEV_EC,fourier49/BIZ_EC,coreboot/chrome-ec,md5555/ec,fourier49/BIZ_EC,coreboot/chrome-ec,md5555/ec,fourier49/BIZ_EC,coreboot/chrome-ec,fourier49/BZ_DEV_EC,md5555/ec,coreboot/chrome-ec,fourier49/BZ_DEV_EC,coreboot/chrome-ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,fourier49/BIZ_EC,akappy7/ChromeOS_EC_LED_Diagnostics,md5555/ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics