mm: remove unused arg of set_page_dirty_balance()

There's only one caller of set_page_dirty_balance() and that will call it
with page_mkwrite == 0.

The page_mkwrite argument was unused since commit b827e496c893 "mm: close
page_mkwrite races".

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7106cb1..ef41349 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1562,9 +1562,9 @@
 		bdi_start_background_writeback(bdi);
 }
 
-void set_page_dirty_balance(struct page *page, int page_mkwrite)
+void set_page_dirty_balance(struct page *page)
 {
-	if (set_page_dirty(page) || page_mkwrite) {
+	if (set_page_dirty(page)) {
 		struct address_space *mapping = page_mapping(page);
 
 		if (mapping)