Clang complains about errors in folly String-inl.h and FBString.h (P1825995)

Summary: fixing clang errors (used clang 3.1)

Test Plan: doh

Reviewed By: tudorb@fb.com

FB internal diff: D622593

folly/FBString.h

@@ -1269,7 +1269,7 @@ public:
     // std::less_equal, which is guaranteed to offer a total order
     // over pointers. See discussion at http://goo.gl/Cy2ya for more
     // info.
-    static const std::less_equal<const value_type*> le;
+    std::less_equal<const value_type*> le;
     if (UNLIKELY(le(oldData, s) && !le(oldData + oldSize, s))) {
       assert(le(s + n, oldData + oldSize));
       const size_type offset = s - oldData;

folly/String-inl.h

@@ -278,7 +278,7 @@ template<class Delim, class String, class OutputType>
 void split(const Delim& delimiter,
            const String& input,
            fbvector<OutputType>& out,
-           bool ignoreEmpty = false) {
+           bool ignoreEmpty) {
   detail::internalSplit<OutputType>(
     detail::prepareDelim(delimiter),
     StringPiece(input),
@@ -451,7 +451,7 @@ void humanify(const String1& input, String2& output) {
 
 template<class InputString, class OutputString>
 bool hexlify(const InputString& input, OutputString& output,
-             bool append_output=false) {
+             bool append_output) {
   if (!append_output) output.clear();
 
   static char hexValues[] = "0123456789abcdef";