Code problems detected by cppcheck

Source/wtf/text/WTFString.h

Index: Source/wtf/text/WTFString.h
diff --git a/Source/wtf/text/WTFString.h b/Source/wtf/text/WTFString.h
index 7c2dffd226923a46e0e06d3c9b3aae7562624495..1e8388eca82d820b48e182861ba69c2c8b1bb555 100644
--- a/Source/wtf/text/WTFString.h
+++ b/Source/wtf/text/WTFString.h
@@ -621,7 +621,7 @@ template<size_t inlineCapacity>
 inline void String::appendTo(Vector<UChar, inlineCapacity>& result, unsigned pos, unsigned len) const
 {
     unsigned numberOfCharactersToCopy = std::min(len, length() - pos);
-    if (numberOfCharactersToCopy <= 0)
+    if (!numberOfCharactersToCopy)
         return;
     result.reserveCapacity(result.size() + numberOfCharactersToCopy);
     if (is8Bit()) {
@@ -638,7 +638,7 @@ template<typename BufferType>
 inline void String::appendTo(BufferType& result, unsigned pos, unsigned len) const
 {
     unsigned numberOfCharactersToCopy = std::min(len, length() - pos);
-    if (numberOfCharactersToCopy <= 0)
+    if (!numberOfCharactersToCopy)
         return;
     if (is8Bit())
         result.append(m_impl->characters8() + pos, numberOfCharactersToCopy);
@@ -650,7 +650,7 @@ template<size_t inlineCapacity>
 inline void String::prependTo(Vector<UChar, inlineCapacity>& result, unsigned pos, unsigned len) const
 {
     unsigned numberOfCharactersToCopy = std::min(len, length() - pos);
-    if (numberOfCharactersToCopy <= 0)
+    if (!numberOfCharactersToCopy)
         return;
     if (is8Bit()) {
         size_t oldSize = result.size();