Properly clean up va_list in SkSL::OutputStream

Change-Id: I8856ab94c0f99edbdf75df36edf88d1cb196fc8d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/310061
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed