Remove dict_table_t::n_foreign_key_checks_running from InnoDB

--source include/have_innodb.inc

create table t1(f1 int not null, primary key(f1))engine=innodb;

create table t2(f1 int not null primary key,

                f2 int not null, foreign key(f2) references t1(f1))engine=innodb;

set DEBUG_SYNC='ib_after_row_insert_step SIGNAL alter WAIT_FOR dml';

--send insert into t1 values(1)

connect(con1,localhost,root,,,);

set DEBUG_SYNC="now WAIT_FOR alter";

alter table t2 force;

set DEBUG_SYNC="now SIGNAL dml";

connection default;

reap;

drop table t2, t1;

disconnect con1;

--source include/have_innodb.inc

create table t1(f1 int not null, primary key(f1))engine=innodb;

create table t2(f1 int not null primary key,

                f2 int not null, foreign key(f2) references t1(f1))engine=innodb;

set DEBUG_SYNC='ib_after_row_insert_step SIGNAL alter WAIT_FOR dml';

--send insert into t2 values(1, 2)

connect(con1,localhost,root,,,);

set DEBUG_SYNC="now WAIT_FOR alter";

alter table t1 force;

set DEBUG_SYNC="now SIGNAL dml";

connection default;

reap;

drop table t2, t1;

disconnect con1;

#6  0x00005555565df591 in lock_wait_suspend_thread (thr=0x7fffb8030768)

    at /home/thiru/mariarepo/10.5/10.5-work/storage/innobase/lock/lock0wait.cc:351

#7  0x00005555566bb378 in row_mysql_handle_errors (new_err=0x7ffff01c3844,

    trx=0x7ffff0cc3268, thr=0x7fffb8030768, savept=0x0)

    at /home/thiru/mariarepo/10.5/10.5-work/storage/innobase/row/row0mysql.cc:740

#8  0x00005555565cd2f7 in lock_table_for_trx (table=0x7fffc41317e8,

    trx=0x7ffff0cc3268, mode=LOCK_X)

    at /home/thiru/mariarepo/10.5/10.5-work/storage/innobase/lock/lock0lock.cc:4070

#9  0x00005555566ad12d in row_merge_lock_table (trx=0x7ffff0cc3268,

    table=0x7fffc41317e8, mode=LOCK_X)

    at /home/thiru/mariarepo/10.5/10.5-work/storage/innobase/row/row0merge.cc:3698

#10 0x0000555556568d42 in ha_innobase::commit_inplace_alter_table (this=

    0x7fffb8020c08, altered_table=0x7ffff01c4fb0,

    ha_alter_info=0x7ffff01c4f20, commit=true)

    at /home/thiru/mariarepo/10.5/10.5-work/storage/innobase/handler/handler0alter.cc:10699

#11 0x000055555611bf0a in handler::ha_commit_inplace_alter_table (

    this=0x7fffb8020c08, altered_table=0x7ffff01c4fb0,

    ha_alter_info=0x7ffff01c4f20, commit=true