Remove some sql_print_error() calls which were triggered by user error (i.e., not server-level events at all).

Also, convert an sql_print_error -> sql_print_information for a non-error server event.


sql/slave.cc:
  Change sql_print_error to sql_print_information for non-error status message.
sql/sql_acl.cc:
  Remove sql_print_error calls for events which are not server errors