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/ceph/caps.c b/fs/ceph/caps.c
index b8731bf..15b21e3 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2363,7 +2363,7 @@
 	}
 
 	if ((issued & CEPH_CAP_LINK_EXCL) == 0)
-		inode->i_nlink = le32_to_cpu(grant->nlink);
+		set_nlink(inode, le32_to_cpu(grant->nlink));
 
 	if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) {
 		int len = le32_to_cpu(grant->xattr_len);