Delete gm after use.

Fixes a memory leak when using the --modulo flag. Instead of deleting
manually in each case we are done with it (which led to missing one
case), use an SkAutoTDelete.

Review URL: https://codereview.chromium.org/13929019

git-svn-id: http://skia.googlecode.com/svn/trunk@8707 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed