Fix FIXME rust-lang#5275

Issue rust-lang#5275 was closed, but there still was a FIXME for it.

src/librustc/middle/liveness.rs

@@ -701,17 +701,12 @@ impl<'a> Liveness<'a> {
                 if self.loop_scope.len() == 0 {
                     self.ir.tcx.sess.span_bug(sp, "break outside loop");
                 } else {
-                    // FIXME(#5275): this shouldn't have to be a method...
-                    self.last_loop_scope()
+                    *self.loop_scope.last().unwrap()
                 }
             }
         }
     }
 
-    fn last_loop_scope(&self) -> NodeId {
-        *self.loop_scope.last().unwrap()
-    }
-
     #[allow(unused_must_use)]
     fn ln_str(&self, ln: LiveNode) -> String {
         let mut wr = io::MemWriter::new();