f2fs: add a tracepoint for f2fs_write_end

This patch adds a tracepoint for f2fs_write_end to trace write op of user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index cde0d69..ea58fb6 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -989,6 +989,8 @@
 {
 	struct inode *inode = page->mapping->host;
 
+	trace_f2fs_write_end(inode, pos, len, copied);
+
 	SetPageUptodate(page);
 	set_page_dirty(page);