Revert my previous patch to make the valgrind bots happy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121461 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index d3a4a27..a1bc9d8 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -24,9 +24,8 @@
 typedef StringMap<const MCSectionCOFF*> COFFUniqueMapTy;
 
 
-MCContext::MCContext(const MCAsmInfo &mai, const TargetAsmInfo *tai) :
-  MAI(mai), TAI(tai), NextUniqueID(0),
-  CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0) {
+MCContext::MCContext(const MCAsmInfo &mai) : MAI(mai), NextUniqueID(0),
+                     CurrentDwarfLoc(0,0,0,DWARF2_FLAG_IS_STMT,0,0) {
   MachOUniquingMap = 0;
   ELFUniquingMap = 0;
   COFFUniquingMap = 0;