Fix bug I introduces with yesterday’s new feature

Change-Id: I5d548e3d75f11904007c10bc982f0ffc1e9073f3
diff --git a/src/lib.rs b/src/lib.rs
index 257c461..a0aee03 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -305,12 +305,16 @@
     }
 }
 
-fn get_target_triple(target_options: &TargetOptions) -> String {
-    let triple_cpu = if (target_options.target_cpu) == X64 {
+fn get_triple_cpu(target_options: &TargetOptions) -> String {
+    if (target_options.target_cpu) == X64 {
         "x86_64"
     } else {
         "aarch64"
-    };
+    }.to_string()
+}
+
+fn get_target_triple(target_options: &TargetOptions) -> String {
+    let triple_cpu = get_triple_cpu(target_options);
 
     format!("{}-unknown-fuchsia", triple_cpu)
 }
@@ -399,8 +403,8 @@
         println!("target_options = {:?}", target_options);
     }
 
-    let triple_cpu = get_target_triple(target_options);
-    let target_triple = format!("{}-unknown-fuchsia", triple_cpu);
+    let triple_cpu = get_triple_cpu(target_options);
+    let target_triple = get_target_triple(target_options);
     let mut target_args = vec!["--target", &target_triple];
 
     if options.release {