Remove some redundant Decl -> Decl castings.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64804 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 5eb2e6a..0d4f562 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2552,11 +2552,10 @@
 /// The declarators are chained together backwards, reverse the list.
 Sema::DeclTy *Sema::FinalizeDeclaratorGroup(Scope *S, DeclTy *group) {
   // Often we have single declarators, handle them quickly.
-  Decl *GroupDecl = static_cast<Decl*>(group);
-  if (GroupDecl == 0)
+  Decl *Group = static_cast<Decl*>(group);
+  if (Group == 0)
     return 0;
   
-  Decl *Group = dyn_cast<Decl>(GroupDecl);
   Decl *NewGroup = 0;
   if (Group->getNextDeclarator() == 0) 
     NewGroup = Group;