buf_pool_resize(): Simplify the fault injection
for innodb.buf_pool_resize_oom.

innodb.buf_pool_resize_oom: Use a small buffer pool.

innodb.innodb_buffer_pool_load_now: Make use of the sequence engine,
to avoid creating explicit InnoDB record locks. Clean up the
accesses to information_schema.innodb_buffer_page_lru.