Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186274 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CallingConvLower.cpp b/lib/CodeGen/CallingConvLower.cpp
index 75f4b96..fcfc9dc 100644
--- a/lib/CodeGen/CallingConvLower.cpp
+++ b/lib/CodeGen/CallingConvLower.cpp
@@ -24,7 +24,7 @@
 using namespace llvm;
 
 CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf,
-                 const TargetMachine &tm, SmallVector<CCValAssign, 16> &locs,
+                 const TargetMachine &tm, SmallVectorImpl<CCValAssign> &locs,
                  LLVMContext &C)
   : CallingConv(CC), IsVarArg(isVarArg), MF(mf), TM(tm),
     TRI(*TM.getRegisterInfo()), Locs(locs), Context(C),