panic: Mark emergency section in warn

panic: Mark emergency section in warn

Mark the full contents of __warn() as an emergency section. In
this section, every printk() call will attempt to directly
flush to the consoles using the EMERGENCY priority.

Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-33-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>