pagevec: Use xa_mark_t

Removes sparse warnings.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 4dd6faa..fc7ca7d9 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3778,7 +3778,7 @@ int btree_write_cache_pages(struct address_space *mapping,
 	pgoff_t index;
 	pgoff_t end;		/* Inclusive */
 	int scanned = 0;
-	int tag;
+	xa_mark_t tag;
 
 	pagevec_init(&pvec);
 	if (wbc->range_cyclic) {
@@ -3903,7 +3903,7 @@ static int extent_write_cache_pages(struct address_space *mapping,
 	pgoff_t done_index;
 	int range_whole = 0;
 	int scanned = 0;
-	int tag;
+	xa_mark_t tag;
 
 	/*
 	 * We have to hold onto the inode so that ordered extents can do their