crash recovery is in progress.  This avoids a hang when
btr_parse_page_reorganize(), called from an I/O handler thread,
attempts to acquire log_sys->mutex while it is being held by
the main thread (the one that runs innobase_init()).  This change
was committed accidentally.  It may be unsafe to clear
mtr.modifications, because buf_page_release() at mtr_commit() may
forget to put modified pages to the flush list.

Cleanup: Remove the "type" parameter from many ibuf functions.
Let the caller check that !dict_index_is_clust().  This should avoid
function calls and register spilling.

ibuf_set_free_bits_func(), ibuf_set_free_bits(): Remove the parameter "type".

ibuf_reset_free_bits_with_type(): Rename to ibuf_reset_free_bits().
Remove the parameter "type".

ibuf_update_free_bits_if_full(), ibuf_update_free_bits_zip(),
ibuf_update_free_bits_low(), ibuf_update_free_bits_for_two_pages_low():
Remove the parameter "index".