powerpc/pseries/cmm: Use adjust_managed_page_count() insted of totalram_pages_*

adjust_managed_page_count() performs a totalram_pages_add(), but also
adjusts the managed pages of the zone. Let's use that instead, similar
to virtio-balloon. Use it before freeing a page.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191031142933.10779-6-david@redhat.com

arch/powerpc/platforms/pseries/cmm.c

@@ -164,7 +164,7 @@ static long cmm_alloc_pages(long nr)
 
 		list_add(&page->lru, &cmm_page_list);
 		loaned_pages++;
-		totalram_pages_dec();
+		adjust_managed_page_count(page, -1);
 		spin_unlock(&cmm_lock);
 		nr--;
 	}
@@ -191,10 +191,10 @@ static long cmm_free_pages(long nr)
 			break;
 		plpar_page_set_active(page);
 		list_del(&page->lru);
+		adjust_managed_page_count(page, 1);
 		__free_page(page);
 		loaned_pages--;
 		nr--;
-		totalram_pages_inc();
 	}
 	spin_unlock(&cmm_lock);
 	cmm_dbg("End request with %ld pages unfulfilled\n", nr);
@@ -518,10 +518,10 @@ static int cmm_mem_going_offline(void *arg)
 			continue;
 		plpar_page_set_active(page);
 		list_del(&page->lru);
+		adjust_managed_page_count(page, 1);
 		__free_page(page);
 		freed++;
 		loaned_pages--;
-		totalram_pages_inc();
 	}
 
 	spin_unlock(&cmm_lock);