Pass StringRef by value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86251 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/TargetLoweringObjectFile.cpp b/lib/Target/TargetLoweringObjectFile.cpp
index c1aab99..3e17058 100644
--- a/lib/Target/TargetLoweringObjectFile.cpp
+++ b/lib/Target/TargetLoweringObjectFile.cpp
@@ -671,7 +671,7 @@
 
 
 const MCSectionMachO *TargetLoweringObjectFileMachO::
-getMachOSection(const StringRef &Segment, const StringRef &Section,
+getMachOSection(StringRef Segment, StringRef Section,
                 unsigned TypeAndAttributes,
                 unsigned Reserved2, SectionKind Kind) const {
   // We unique sections by their segment/section pair.  The returned section