Argument BTRFS_FILE_EXTENT_INLINE_DATA_START is defined as offsetof(),
which returns type size_t, so we need %zu instead of %lu.
This fixes a build warning on 32-bit ARM:
  ../fs/btrfs/tree-checker.c: In function 'check_extent_data_item':
  ../fs/btrfs/tree-checker.c:230:43: warning: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'unsigned int' [-Wformat=]
    230 |     "invalid item size, have %u expect [%lu, %u)",
        |                                         ~~^
        |                                           long unsigned int
        |                                         %u
Fixes: 153a6d299956 ("btrfs: tree-checker: Check item size before reading file extent type")
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andreas Färber <afaerber@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
         */
        if (item_size < BTRFS_FILE_EXTENT_INLINE_DATA_START) {
                file_extent_err(leaf, slot,
-                               "invalid item size, have %u expect [%lu, %u)",
+                               "invalid item size, have %u expect [%zu, %u)",
                                item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START,
                                SZ_4K);
                return -EUCLEAN;