crypto/internal/fips: make linknames path-independent

When using a FIPS140 snapshot, the import paths will have
FIPS version numbers in them, so use explicit import paths
for coordination with package runtime, which expects
crypto/internal/fips, not (say) crypto/internal/fips/v1.1.

Change-Id: I3ac48c84810493152e039eaa5f44d7cfe13d35f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/627915
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Russ Cox <rsc@golang.org>

src/crypto/internal/fips/cast.go

@@ -13,7 +13,7 @@ import (
 
 // fatal is [runtime.fatal], pushed via linkname.
 //
-//go:linkname fatal
+//go:linkname fatal crypto/internal/fips.fatal
 func fatal(string)
 
 // failfipscast is a GODEBUG key allowing simulation of a Cryptographic Algorithm

src/crypto/internal/fips/indicator.go

@@ -16,10 +16,10 @@ import _ "unsafe" // for go:linkname
 // negative. Finally, we expose indicatorUnset as negative to the user, so that
 // we don't need to explicitly annotate fully non-approved services.
 
-//go:linkname getIndicator
+//go:linkname getIndicator crypto/internal/fips.getIndicator
 func getIndicator() uint8
 
-//go:linkname setIndicator
+//go:linkname setIndicator crypto/internal/fips.setIndicator
 func setIndicator(uint8)
 
 const (