Don't hardcode the %reg format in the streamer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132451 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCInstPrinter.cpp b/lib/MC/MCInstPrinter.cpp
index 212b85e..81a939f 100644
--- a/lib/MC/MCInstPrinter.cpp
+++ b/lib/MC/MCInstPrinter.cpp
@@ -20,7 +20,6 @@
   return "";
 }
 
-StringRef MCInstPrinter::getRegName(unsigned RegNo) const {
+void MCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
   assert(0 && "Target should implement this");
-  return "";
 }