livePhysRegs: Pass MBB by reference in addLive{Ins|Outs}(); NFC

The block must no be nullptr for the addLiveIns()/addLiveOuts()
function.

llvm-svn: 268340
diff --git a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
index ed74d20..31828a3 100644
--- a/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ b/llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -467,7 +467,7 @@
   // Look for a temporary register to use.
   // First, compute the liveness information.
   LivePhysRegs UsedRegs(STI.getRegisterInfo());
-  UsedRegs.addLiveOuts(&MBB);
+  UsedRegs.addLiveOuts(MBB);
   // The semantic of pristines changed recently and now,
   // the callee-saved registers that are touched in the function
   // are not part of the pristines set anymore.