[VPlan] Improve code using VPlan::getFalse (NFC)

Author: artagnon

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1110,8 +1110,7 @@ static void simplifyRecipe(VPRecipeBase &R, VPTypeAnalysis &TypeInfo) {
 
   // x && !x -> 0
   if (match(&R, m_LogicalAnd(m_VPValue(X), m_Not(m_Deferred(X)))))
-    return Def->replaceAllUsesWith(Plan->getOrAddLiveIn(
-        ConstantInt::getFalse(VPTypeAnalysis(*Plan).inferScalarType(Def))));
+    return Def->replaceAllUsesWith(Plan->getFalse());
 
   if (match(Def, m_Select(m_VPValue(), m_VPValue(X), m_Deferred(X))))
     return Def->replaceAllUsesWith(X);