Fixing problem in injector code making NDB tests fire an assertion.

sql/ha_ndbcluster_binlog.cc:
  Removing extreneous setting of current_stmt_binlog_row_based.
sql/rpl_injector.cc:
  Since current_stmt_binlog_row_based is reset as the end of a transaction
  it needs to be set at the beginning of a transaction.

sql/ha_ndbcluster_binlog.cc

@@ -3436,7 +3436,6 @@ pthread_handler_t ndb_binlog_thread_func(void *arg)
         global_system_variables.binlog_format == BINLOG_FORMAT_MIXED)
     {
       ndb_binlog_running= TRUE;
-      thd->current_stmt_binlog_row_based= TRUE;     // If in mixed mode
     }
     else
     {

sql/rpl_injector.cc

@@ -39,6 +39,8 @@ injector::transaction::transaction(MYSQL_BIN_LOG *log, THD *thd)
   m_start_pos.m_file_pos= log_info.pos;
 
   begin_trans(m_thd);
+
+  thd->set_current_stmt_binlog_row_based();
 }
 
 injector::transaction::~transaction()