Historical leftovers from the time where kmap() had fixed slots.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid Sterba <dsterba@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20201103095856.870272797@linutronix.de