cmd/go, cmd/link: use "Go" not "GO" as ELF note identifier

Change-Id: I038e892725836ab7718f7638e8ad5712953f2cb5
Reviewed-on: https://go-review.googlesource.com/10704Reviewed-by: Ian Lance Taylor <iant@golang.org>

misc/cgo/testshared/shared_test.go

@@ -399,7 +399,7 @@ func TestNotes(t *testing.T) {
 	abiHashNoteFound := false
 	depsNoteFound := false
 	for _, note := range notes {
-		if note.name != "GO\x00\x00" {
+		if note.name != "Go\x00\x00" {
 			continue
 		}
 		switch note.tag {

src/cmd/go/build.go

@@ -751,7 +751,7 @@ func goFilesPackage(gofiles []string) *Package {
 }
 
 func readpkglist(shlibpath string) []*Package {
-	pkglistbytes, err := readELFNote(shlibpath, "GO\x00\x00", 1)
+	pkglistbytes, err := readELFNote(shlibpath, "Go\x00\x00", 1)
 	if err != nil {
 		fatalf("readELFNote failed: %v", err)
 	}

src/cmd/link/internal/ld/elf.go

@@ -1210,7 +1210,7 @@ const (
 	ELF_NOTE_GODEPS_TAG    = 3
 )
 
-var ELF_NOTE_GO_NAME = []byte("GO\x00\x00")
+var ELF_NOTE_GO_NAME = []byte("Go\x00\x00")
 
 var elfverneed int