Do not misspell "fall through"

Author: dr-m

sql/sql_trigger.cc

@@ -1595,7 +1595,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
  thd->spcont= save_spcont;
  thd->variables.sql_mode= save_sql_mode;
  thd->reset_db(save_db.str, save_db.length);
- /* Fall trough to error */
+ /* Fall through to error */
  }
  }
 

sql/table.cc

@@ -7419,7 +7419,6 @@ int TABLE::update_virtual_fields(handler *h, enum_vcol_update_mode update_mode)
  swap_values= 1;
  break;
  case VCOL_UPDATE_FOR_DELETE:
- /* Fall trough */
  case VCOL_UPDATE_FOR_WRITE:
  update= bitmap_is_set(vcol_set, vf->field_index);
  break;