Fix typo.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176603 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 2f349fa..7e966a0 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -793,7 +793,7 @@
     return getStorageClass() == SC_Static && !isFileVarDecl();
   }
 
-  /// hasExternStorage - Returns true if a variable has extern or
+  /// hasExternalStorage - Returns true if a variable has extern or
   /// __private_extern__ storage.
   bool hasExternalStorage() const {
     return getStorageClass() == SC_Extern ||