Properly test the LLVM_USE_RVALUE_REFERENCES macro.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Unix/PathV2.inc b/lib/Support/Unix/PathV2.inc
index 3bb38f6..d04f590 100644
--- a/lib/Support/Unix/PathV2.inc
+++ b/lib/Support/Unix/PathV2.inc
@@ -545,7 +545,7 @@
     ::munmap(Mapping, Size);
 }
 
-#ifdef LLVM_USE_RVALUE_REFERENCES
+#if LLVM_USE_RVALUE_REFERENCES
 mapped_file_region::mapped_file_region(mapped_file_region &&other)
   : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
   other.Mapping = 0;