internal/trace/v2: make readBatch param more permissive
This function is copied to x/exp/trace. In https://go.dev/cl/566255 a
change is made where the source is a bytes.Reader instead of a
bufio.Reader from one of the two callers. Change the prototype here
instead of diverging the implementations.
Change-Id: I594224663996eadbc8c388442d68ac5706c52c8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/566236
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>