Use isa instead of dyn_cast.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55207 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 3ece5fc..fd1b3e7 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -407,8 +407,7 @@
     priority = Idx.getZExtValue();
   }
   
-  FunctionDecl *Fn = dyn_cast<FunctionDecl>(d);
-  if (!Fn) {
+  if (!isa<FunctionDecl>(d)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type,
            "destructor", "function");
     return;