Add jbd2_journal_init_global() which initializes the JBD2 journal
subsystem caches. This wraps the existing journal_init() with a
static guard to ensure it's only called once.
Call this from ext4l_probe() when CONFIG_EXT4_JOURNAL is enabled
to initialize the journal subsystem before any journal operations.
Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
19de128635