HostToolPath should return install path

Bug: 163154468
Test: make; find dependencies of 'Module:  sqlite3_bindgen_x86_64'
Change-Id: Id9fc4f1937983bdf7eb1732ed6a8afd5aa3eb24c
diff --git a/rust/rust.go b/rust/rust.go
index edfa5d8..46159c6 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -1057,8 +1057,8 @@
 	if !mod.Host() {
 		return android.OptionalPath{}
 	}
-	if _, ok := mod.compiler.(*binaryDecorator); ok {
-		return mod.outputFile
+	if binary, ok := mod.compiler.(*binaryDecorator); ok {
+		return android.OptionalPathForPath(binary.baseCompiler.path)
 	}
 	return android.OptionalPath{}
 }