fiddle: Fix the linking of fiddle_main under cmake.
fiddle: Fix the linking of fiddle_main under cmake.

BUG=skia:

Review-Url: https://codereview.chromium.org/2209533002

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot