Revert "Fix unit test after merge from mysql 5.5.35 perfschema"

This reverts commit 4799af09.

Upstream provided adequate fix. This commit is no longer necessary.

storage/perfschema/unittest/pfs-t.cc

@@ -1339,7 +1339,6 @@ void test_locker_disabled()
   /* Pretend the socket does not have a thread owner */
   /* ---------------------------------------------- */
 
-  psi->delete_current_thread();
   socket_class_A->m_enabled= true;
   socket_A1= psi->init_socket(socket_key_A, NULL, NULL, 0);
   ok(socket_A1 != NULL, "instrumented");