NFS: Off-by-one length error in string handling

The hostname was getting truncated in the new text-based NFS mount API.

Signed-off-by: Chuck Lever <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/super.c

···
 		c = strchr(dev_name, ':');
 		if (c == NULL)
 			return -EINVAL;
-		len = c - dev_name - 1;
+		len = c - dev_name;
 		if (len > sizeof(data->hostname))
 			return -EINVAL;
 		strncpy(data->hostname, dev_name, len);