Remove double free in GM and Bench.

Since the SkArenaAlloc handles calling the dtor, it is not longer needed
in the test.

Change-Id: I70a09be7bd0e71bf1e3d55ef08b5e87742e0bd18
Reviewed-on: https://skia-review.googlesource.com/8191
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
2 files changed