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/proc/generic.c b/fs/proc/generic.c
index 9d99131..10090d9 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -283,7 +283,7 @@
 	struct inode *inode = dentry->d_inode;
 	struct proc_dir_entry *de = PROC_I(inode)->pde;
 	if (de && de->nlink)
-		inode->i_nlink = de->nlink;
+		set_nlink(inode, de->nlink);
 
 	generic_fillattr(inode, stat);
 	return 0;