util/ectool: Fix llvm compiler errors
util/ectool: Fix llvm compiler errors

BUG=chromium:668259
BRANCH=None
TEST=Manual on samus (w/ gcc-built ectool).
Verify 'ectool pause_in_s5 [on|off]' followed by 'ectool pause_in_s5'
reflects the new updated state.
Verify 'ectool --name=cros_pd flashpd 0 1 ec.RW.bin' succeeds to flash
valid zinger RW image.
Also verify `emerge-nyan_big ec-utils` succeeds w/ new llvm toolchain.

Change-Id: Ibe83ee0fc0b2e6f535ed822603f438ed62350d29
Signed-off-by: Shawn Nematbakhsh <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/419797
Commit-Ready: Shawn N <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>
Tested-by: Shawn N <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>
Reviewed-by: Manoj Gupta <1d49d0f302d724a1dc5fc4d717d15418e9808ddd@chromium.org>
Reviewed-by: Randall Spangler <62698fdbb84d1779579ee80c3f39fac22017e5bc@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec