Clean up String.indexOf() intrinsics.

Additional cleanup after
    https://android-review.googlesource.com/223260

Bug: 28330359
Change-Id: I88def196babec70123896ef581ec8d61bb1b9a9a
diff --git a/compiler/optimizing/intrinsics_x86_64.cc b/compiler/optimizing/intrinsics_x86_64.cc
index 4ee2368..06e9cc2 100644
--- a/compiler/optimizing/intrinsics_x86_64.cc
+++ b/compiler/optimizing/intrinsics_x86_64.cc
@@ -1521,7 +1521,7 @@
   SlowPathCode* slow_path = nullptr;
   HInstruction* code_point = invoke->InputAt(1);
   if (code_point->IsIntConstant()) {
-    if (static_cast<uint32_t>(invoke->InputAt(1)->AsIntConstant()->GetValue()) >
+    if (static_cast<uint32_t>(code_point->AsIntConstant()->GetValue()) >
     std::numeric_limits<uint16_t>::max()) {
       // Always needs the slow-path. We could directly dispatch to it, but this case should be
       // rare, so for simplicity just put the full slow-path down and branch unconditionally.