eliminate extraneous choice point in $get_attr

src/prolog/lib/atts.pl

@@ -24,7 +24,7 @@
 '$get_from_list'([L|Ls], V, Attr) :-
     nonvar(L),
     ( L \= Attr -> nonvar(Ls), '$get_from_list'(Ls, V, Attr)
-    ; L = Attr, '$enqueue_attr_var'(V)
+    ; L = Attr -> '$enqueue_attr_var'(V)
     ; '$get_from_list'(Ls, V, Attr)
     ).
 

src/prolog/machine/system_calls.rs

@@ -1252,7 +1252,7 @@ impl MachineState {
             &SystemClauseType::GetAttributedVariableList => {
                 let attr_var = self.store(self.deref(self[temp_v!(1)].clone()));
                 let attr_var_list = match attr_var {
-                    Addr::AttrVar(h) => h + 1,
+                    Addr::AttrVar(h) => h + 1,                    
                     attr_var @ Addr::HeapCell(_) | attr_var @ Addr::StackCell(..) => {
                         // create an AttrVar in the heap.
                         let h = self.heap.h;