crypto/x509: optimize the performance of checkSignature
The loop should be terminated immediately when `algo` has been found
Fixes #52955
Change-Id: Ib3865c4616a0c1af9b72daea45f5a1750f84562f
GitHub-Last-Rev:
721322725fb2d3a3ea410d09fd8320dfef865d8d
GitHub-Pull-Request: golang/go#52987
Reviewed-on: https://go-review.googlesource.com/c/go/+/407215
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Auto-Submit: Roland Shoemaker <roland@golang.org>