consolidate compat lookup_dcookie()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 395084d..b50e2a0 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -20,6 +20,7 @@
 cond_syscall(sys32_quotactl);
 cond_syscall(sys_acct);
 cond_syscall(sys_lookup_dcookie);
+cond_syscall(compat_sys_lookup_dcookie);
 cond_syscall(sys_swapon);
 cond_syscall(sys_swapoff);
 cond_syscall(sys_kexec_load);