Print the promo watermark in zoneinfo just like other watermarks.  This
helps users check and verify all the watermarks are appropriate.
Link: https://lkml.kernel.org/r/20240801232548.36604-3-kaiyang2@cs.cmu.edu
Signed-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
                   "\n        min      %lu"
                   "\n        low      %lu"
                   "\n        high     %lu"
+                  "\n        promo    %lu"
                   "\n        spanned  %lu"
                   "\n        present  %lu"
                   "\n        managed  %lu"
                   min_wmark_pages(zone),
                   low_wmark_pages(zone),
                   high_wmark_pages(zone),
+                  promo_wmark_pages(zone),
                   zone->spanned_pages,
                   zone->present_pages,
                   zone_managed_pages(zone),