innobase/include/lock0lock.h:
  Improve comments regarding LOCK_TABLE_EXP
innobase/include/row0mysql.h:
  Rename row_unlock_table_for_mysql() to row_unlock_tables_for_mysql()
  and improve its comment
innobase/include/trx0trx.h:
  Rename n_tables_locked to n_lock_table_exp
innobase/lock/lock0lock.c:
  Rename n_tables_locked to n_lock_table_exp
  Increment n_lock_table_exp already in lock_table_create()
  Replace some ut_ad() assertions with ut_a()
innobase/row/row0mysql.c:
  Rename n_tables_locked to n_lock_table_exp
  Rename row_unlock_table_for_mysql() to row_unlock_tables_for_mysql()
  and improve its comment
innobase/trx/trx0trx.c:
  Rename n_tables_locked to n_lock_table_exp
sql/ha_innodb.cc:
  Rename n_tables_locked to n_lock_table_exp
  Rename row_unlock_table_for_mysql() to row_unlock_tables_for_mysql()