During code review, `CASE` was renamed to `TFJ_CASE`, but one occurrence still refers to the old name. This patch fixes that.

Ref. 2c995c8c

R=danno@chromium.org
BUG=v8:1956
LOG=N

Review-Url: https://codereview.chromium.org/2854913002
Cr-Commit-Position: refs/heads/master@{#45040}