[PATCH] mm: include linux/pagemap.h where needed

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

The pagemap header used to be included by accident here but is now
missing:

mm/z3fold.c: In function 'free_z3fold_page':
mm/z3fold.c:353:17: error: implicit declaration of function 'lock_page'; did you mean 'copy_page'? [-Wimplicit-function-declaration]
  353 |                 lock_page(page);
      |                 ^~~~~~~~~
      |                 copy_page

Add the correct #include statement.

Fixes: a6c37165ca40 ("mempolicy.h: remove unnecessary header file inclusions with no test failure")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 mm/z3fold.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/z3fold.c b/mm/z3fold.c
index 379d24b4fef9..4ae93bb2e3ab 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -30,6 +30,7 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/page-flags.h>
+#include <linux/pagemap.h>
 #include <linux/migrate.h>
 #include <linux/node.h>
 #include <linux/compaction.h>
-- 
2.39.5