archive/tar: check returned error before use hdr
Change-Id: I8c28dac73427e37d58d970b00d8f0f1413bede2e
GitHub-Last-Rev:
a11a8036028ecf6f811b1470becc924b77a2c734
GitHub-Pull-Request: golang/go#65932
Reviewed-on: https://go-review.googlesource.com/c/go/+/566695
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>