NFS: Fix cache consistency regression

Make sure cache_change_attribute is initialized to jiffies
so when the mtime changes on directory, the directory
will be refreshed.

Signed-off by: Steve Dickson <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/inode.c

···
 		return NULL;
 	nfsi->flags = 0UL;
 	nfsi->cache_validity = 0UL;
+	nfsi->cache_change_attribute = jiffies;
 #ifdef CONFIG_NFS_V3_ACL
 	nfsi->acl_access = ERR_PTR(-EAGAIN);
 	nfsi->acl_default = ERR_PTR(-EAGAIN);