runtime/internal/atomic: correct GOARM=7 guard at a DMB instruction
CL 525637 changed to the guard of DMB instruction from the
compiled-in runtime.goarm value to GOARM_7 macro and CPU feature
detection. It missed a place where runtime.goarm is loaded to a
register and reused later. This CL corrects the condition.
Fixes #65601.
Change-Id: I2ddefd03a1eb1048dbec0254c6e234c65b054279
Reviewed-on: https://go-review.googlesource.com/c/go/+/564855
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Keith Randall <khr@golang.org>