internal/zstd: reset reader buffer
Reset r.buffer on Reset to avoid subsequent Read calls
observing previously decoded data.
For #62513
Change-Id: Icb65e76b5c5c0af32b36ec3a5999dca86407cbc8
GitHub-Last-Rev:
99c0a6fa72ad67cba5d29593fd3b28d14ddce4a4
GitHub-Pull-Request: golang/go#63288
Reviewed-on: https://go-review.googlesource.com/c/go/+/531735
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>