runtime: fix comment about memequal implementation locations

Change-Id: I9ae3f462a6a6b3809de14b0d08f369524b636d57
Reviewed-on: https://go-review.googlesource.com/c/go/+/237097
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go
index 2c6f027..b891a12 100644
--- a/src/runtime/stubs.go
+++ b/src/runtime/stubs.go
@@ -130,7 +130,7 @@
 //go:linkname sync_fastrand sync.fastrand
 func sync_fastrand() uint32 { return fastrand() }
 
-// in asm_*.s
+// in internal/bytealg/equal_*.s
 //go:noescape
 func memequal(a, b unsafe.Pointer, size uintptr) bool