Revert "Add return for 1.8.7"

This reverts commit 665ef116.

There is no need for the return anymore, so reverting.

activerecord/test/cases/relation_scoping_test.rb

@@ -533,7 +533,7 @@ def test_default_scope_include_with_count
 
   def test_default_scope_is_threadsafe
     if in_memory_db?
-      return skip "in memory db can't share a db between threads"
+      skip "in memory db can't share a db between threads"
     end
 
     threads = []