Fix crash in linting

Redeclared functions in non-whole-program analyze mode caused
an assertion failure.

Test Plan:
  % cat bug.php
  <?php
  if (isset($g)) {
    function f($x, $y) {}
  } else {
    function f($x) {}
  }
  f($x);
  % hphp -vWholeProgram=false -t analyze bug.php

hphp/compiler/expression/simple_function_call.cpp

@@ -1128,7 +1128,7 @@ TypePtr SimpleFunctionCall::inferAndCheck(AnalysisResultPtr ar, TypePtr type,
         setAttribute(VariableTable::NeedGlobalPointer);
     }
     if (m_params) {
-      if (func && func->isRedeclaring()) {
+      if (Option::WholeProgram && func && func->isRedeclaring()) {
         FunctionScope::FunctionInfoPtr info =
           FunctionScope::GetFunctionInfo(m_name);
         always_assert(info);