- Remove the printf support leaving the direct printk support configured
with TESTS_USE_PRINTK and all other output goes via a buffered vsniprintf
call to printk.
- Control the test's single init for functions and global data with
TEST_INIT and not CONFIGURE_INIT. They are now separate.
Updates #3170.
The set block size must synchronize and purge the disk to avoid an
inconsistent cache state and data corruption. The synchronization is
optional depending on the new sync parameter. In some contexts a
synchronization must not be performed, e.g. during disk creation.