Fix linked_list::remove_if()

When remove_if removes last element from the list
following push_back stops working.

Change-Id: Ia3e92763b83a2e172eaa10de7aecfb7a4be452d7
diff --git a/linker/linked_list.h b/linker/linked_list.h
index 8003dbf..eb3ecd4 100644
--- a/linker/linked_list.h
+++ b/linker/linked_list.h
@@ -127,6 +127,11 @@
         } else {
           p->next = next;
         }
+
+        if (tail_ == e) {
+          tail_ = p;
+        }
+
         Allocator::free(e);
         e = next;
       } else {