encoding/json: remove use of DeepEqual for testing errors
encoding/json: remove use of DeepEqual for testing errors

Comparing errors using DeepEqual breaks if frame information
is added as proposed in Issue #29934.

Updates #29934.

Change-Id: Ib430c9ddbe588dd1dd51314c408c74c07285e1ff
Reviewed-on: https://go-review.googlesource.com/c/162179
Run-TryBot: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
Reviewed-by: Damien Neil <7e091e9a80da888fcd7836fd3c6b7b85f4677c12@google.com>

coreos/go-json