vfs: export filemap_fdatawrite_range()

Make filemap_fdatawrite_range() function public, so that it can later
be used in ordered mode rewrite by JBD/JBD2.

Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d8e2762..97f992a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1740,6 +1740,8 @@
 				pgoff_t start, pgoff_t end);
 extern int __filemap_fdatawrite_range(struct address_space *mapping,
 				loff_t start, loff_t end, int sync_mode);
+extern int filemap_fdatawrite_range(struct address_space *mapping,
+				loff_t start, loff_t end);
 
 extern long do_fsync(struct file *file, int datasync);
 extern void sync_supers(void);