rb_gc_impl_define_finalizer: unlock on early return

Author: byroot

gc/mmtk/mmtk.c

@@ -986,6 +986,7 @@ rb_gc_impl_define_finalizer(void *objspace_ptr, VALUE obj, VALUE block)
             for (i = 0; i < len; i++) {
                 VALUE recv = RARRAY_AREF(table, i);
                 if (rb_equal(recv, block)) {
+                    rb_gc_vm_unlock(lev);
                     return recv;
                 }
             }