Really fix build.

Change-Id: I09c76b8fede9e926519b206010ba6c7ab44c3216
diff --git a/src/compiler/codegen/MethodCodegenDriver.cc b/src/compiler/codegen/MethodCodegenDriver.cc
index db491f1..6b3283e 100644
--- a/src/compiler/codegen/MethodCodegenDriver.cc
+++ b/src/compiler/codegen/MethodCodegenDriver.cc
@@ -40,7 +40,11 @@
 {
     RegLocation res = LOC_C_RETURN;
     oatClobber(cUnit, res.lowReg);
-    oatLockTemp(cUnit, res.lowReg);
+    if (cUnit->instructionSet == kMips) {
+        oatMarkInUse(cUnit, res.lowReg);
+    } else {
+        oatLockTemp(cUnit, res.lowReg);
+    }
     return res;
 }