runtime/cgo: avoid errors from -Wdeclaration-after-statement
CL 652181 accidentally missed this iPhone only code.
For #71961
Change-Id: I567f8bb38958907442e69494da330d5199d11f54
Reviewed-on: https://go-review.googlesource.com/c/go/+/653135
Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com>