cmd/go/internal/vgo: eliminate the redundant isGetU variable

isGetU is invariantly equal to *getU, and both variables are
unexported and mentioned in the same files: the extra variable adds
indirection but no apparent abstraction at this point in time.

Change-Id: I0f4d86405732bb9c7efb259ee68fe63f0d1a3ef4
Reviewed-on: https://go-review.googlesource.com/119735
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/vendor/cmd/go/internal/vgo/get.go b/vendor/cmd/go/internal/vgo/get.go
index 988e50d..ce632bf 100644
--- a/vendor/cmd/go/internal/vgo/get.go
+++ b/vendor/cmd/go/internal/vgo/get.go
@@ -50,7 +50,6 @@
 	}
 
 	if *getU {
-		isGetU = true
 		ImportPaths([]string{"."})
 		return
 	}
diff --git a/vendor/cmd/go/internal/vgo/load.go b/vendor/cmd/go/internal/vgo/load.go
index de89526..28fbab3 100644
--- a/vendor/cmd/go/internal/vgo/load.go
+++ b/vendor/cmd/go/internal/vgo/load.go
@@ -42,7 +42,6 @@
 	importmap map[string]string
 	pkgdir    map[string]string
 	pkgmod    map[string]module.Version
-	isGetU    bool
 )
 
 func AddImports(gofiles []string) {
@@ -170,7 +169,7 @@
 func iterate(doImports func(*loader)) {
 	var err error
 	mvsOp := mvs.BuildList
-	if isGetU {
+	if *getU {
 		mvsOp = mvs.UpgradeAll
 	}
 	buildList, err = mvsOp(Target, newReqs())