Reduce variable scope and possibly useless palloc

Move the CreateStmt down to the branch that it's used in, thus
preventing the makeNode() call in cases where the CreateStmt isn't used.

Author: Ranier Vilela <ranier.vf@gmail.com>
Discussion: https://postgr.es/m/CAEudQAq=06YPWPhS+yyTbCwv5JLKRz8rm3dWx6JR5Uj_d_fQDA@mail.gmail.com

src/backend/commands/view.c

@@ -47,7 +47,6 @@ DefineVirtualRelation(RangeVar *relation, List *tlist, bool replace,
 {
 	Oid			viewOid;
 	LOCKMODE	lockmode;
-	CreateStmt *createStmt = makeNode(CreateStmt);
 	List	   *attrList;
 	ListCell   *t;
 
@@ -223,6 +222,7 @@ DefineVirtualRelation(RangeVar *relation, List *tlist, bool replace,
 	}
 	else
 	{
+		CreateStmt *createStmt = makeNode(CreateStmt);
 		ObjectAddress address;
 
 		/*