[clang] NFC: Remove else if after return

[kbobyrev]

Summary

Update the code to be compatible with LLVM Coding Guidelines.

[sammccall]

Thanks! (trivial changes like this can also be submitted without review)

clang/lib/AST/DeclBase.cpp

bool DeclContext::isDependentContext() const {
   // should be considered dependent.
 
   return getParent() && getParent()->isDependentContext();
 }
 
 bool DeclContext::isTransparentContext() const {
   if (getDeclKind() == Decl::Enum)
     return !cast<EnumDecl>(this)->isScoped();
-  else if (getDeclKind() == Decl::LinkageSpec || getDeclKind() == Decl::Export)
-    return true;
 
-  return false;
+  return getDeclKind() == Decl::LinkageSpec || getDeclKind() == Decl::Export;
 }
 
 static bool isLinkageSpecContext(const DeclContext *DC,
                                  LinkageSpecDecl::LanguageIDs ID) {
   while (DC->getDeclKind() != Decl::TranslationUnit) {
     if (DC->getDeclKind() == Decl::LinkageSpec)
       return cast<LinkageSpecDecl>(DC)->getLanguage() == ID;
     DC = DC->getLexicalParent();