Deal with missing exports for hostfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/um/kernel/ksyms.c

@@ -58,6 +58,9 @@ EXPORT_SYMBOL(os_accept_connection);
 EXPORT_SYMBOL(os_rcv_fd);
 EXPORT_SYMBOL(run_helper);
 EXPORT_SYMBOL(start_thread);
+EXPORT_SYMBOL(os_major);
+EXPORT_SYMBOL(os_minor);
+EXPORT_SYMBOL(os_makedev);
 
 EXPORT_SYMBOL(add_sigio_fd);
 EXPORT_SYMBOL(ignore_sigio_fd);