filesystems: add set_nlink()

Replace remaining direct i_nlink updates with a new set_nlink()
updater function.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 78418b4..1656df7 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -299,7 +299,7 @@
 		if (nlink == 0)
 			clear_nlink(inode);
 		else
-			inode->i_nlink = nlink;
+			set_nlink(inode, nlink);
 	}
 }