AttributeList: tweak the conditional order to avoid two strcmps

llvm-svn: 196518
diff --git a/clang/lib/Sema/AttributeList.cpp b/clang/lib/Sema/AttributeList.cpp
index aa7f9df..023069c 100644
--- a/clang/lib/Sema/AttributeList.cpp
+++ b/clang/lib/Sema/AttributeList.cpp
@@ -122,8 +122,8 @@
   StringRef AttrName = Name->getName();
 
   // Normalize the attribute name, __foo__ becomes foo.
-  if (AttrName.startswith("__") && AttrName.endswith("__") &&
-      AttrName.size() >= 4)
+  if (AttrName.size() >= 4 && AttrName.startswith("__") &&
+      AttrName.endswith("__"))
     AttrName = AttrName.substr(2, AttrName.size() - 4);
 
   SmallString<64> Buf;