internal/rosa: remove global handles

These no longer serve any purpose.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -122,7 +122,7 @@ func main() {
 		rosa.Native().DropCaches("", flags)
 		cross := flagArch != "" && flagArch != runtime.GOARCH
 		if flagQEMU || cross {
-			_, cm.qemu = rosa.Native().Std().MustLoad(rosa.QEMU)
+			_, cm.qemu = rosa.Native().Std().MustLoad(rosa.H("qemu"))
 		}
 
 		if cross {
@@ -769,7 +769,7 @@ func main() {
 
 				base := rosa.LLVM
 				if !flagWithToolchain {
-					base = rosa.Musl
+					base = rosa.H("musl")
 				}
 				handles = append(handles,
 					base,