Remove redundant tree_height check from btr_cur_pessimistic_update().
Simplify row_update_cascade_for_mysql() by returning early in case of
fake changes.
Rename rpl/rpl_percona_fake_changes testcase to
binlog/binlog_percona_fake_changes, simplify it to remove slave server
setup and only check binlog on the remaining server.
Remove Innodb_buffer_pool_pages_dirty and
Innodb_buffer_pool_write_requests checks around fake changes workload
in percona_innodb_fake_changes_stats because, depending on the server
load and previously-executed MTR testcases in the run, a buffer pool
page might be dirtied by an InnoDB background task still cleaning up
from a previous testcase.