nfsd: Remove write permission from file content

The write function doesn't be implemented in file content, and it's meaningless
to write data into this file directly. Remove write permission from it.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

net/sunrpc/cache.c

@@ -1614,7 +1614,7 @@ static int create_cache_proc_entries(struct cache_detail *cd, struct net *net)
 			goto out_nomem;
 	}
 	if (cd->cache_show) {
-		p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR,
+		p = proc_create_data("content", S_IFREG|S_IRUSR,
 				cd->u.procfs.proc_ent,
 				&content_file_operations_procfs, cd);
 		cd->u.procfs.content_ent = p;