The doublewrite buffer pages must fit in the first InnoDB system
tablespace data file. The checks that were added in the initial patch
(commit 112b21da)
were at too high level and did not cover all cases.

innodb.log_data_file_size: Test all innodb_page_size combinations.

fsp_header_init(): Never return an error. Move the change buffer creation
to the only caller that needs to do it.

btr_create(): Clean up the logic. Remove the error log messages.

buf_dblwr_create(): Try to return an error on non-fatal failure.
Check that the first data file is big enough for creating the
doublewrite buffers.

buf_dblwr_process(): Check if the doublewrite buffer is available.
Display the message only if it is available.

recv_recovery_from_checkpoint_start_func(): Remove a redundant message
about FIL_PAGE_FILE_FLUSH_LSN mismatch when crash recovery has already
been initiated.

fil_report_invalid_page_access(): Simplify the message.

fseg_create_general(): Do not emit messages to the error log.

innobase_init(): Revert the changes.

trx_rseg_create(): Refactor (no functional change).