npcx/i2c: Rename variable for clarity
npcx/i2c: Rename variable for clarity

BRANCH=none
BUG=b:201039003
TEST=buildall passes

Change-Id: I5b34e5266f28452d30d76489e4afaef4cb2287e2
Signed-off-by: Caveh Jalali <08e24a66aefda7a55ca7d73f8903e0fb16eec763@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3181501
Reviewed-by: Daisuke Nojiri <fd5f93af191bf7e8f73ea71cc3c0f66b41b1dd49@chromium.org>

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