Fix typo in yasm dummy DEPS.

Was specifying jsoncpp_revision instead of patched_yasm_revision.

Bug: 1017514
Change-Id: Ib16f9bb28843c17c24fabcf344fdaf50846b4a5e
Tbr: dpranke@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1882087
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#709745}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 3d374fff51f3c0432f7fad04043ff0e318bfec83