nfs: fix handling of invalid mount options in nfs_remount

nfs_parse_mount_options returns 0 on error, not -errno.
Reported-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/super.c

@@ -2205,8 +2205,8 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
 		data->nfs_server.addrlen);
 
 	/* overwrite those values with any that were specified */
-	error = nfs_parse_mount_options((char *)options, data);
-	if (error < 0)
+	error = -EINVAL;
+	if (!nfs_parse_mount_options((char *)options, data))
 		goto out;
 
 	/*