Signal invalid ipc operation with ENOSYS

The ipc multiplexer syscall on x86 currently returns EINVAL for a non-existing sub-opcode. This logical but is a problem with the introduction of new operations (like semtimedop). Now EINVAL can mean "no such operation" and "invalid parameter". To avoid such problems in future, could you apply the attached patch?

--------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------

@@ -204,7 +204,7 @@
 		return sys_shmctl (first, second,
 				   (struct shmid_ds *) ptr);
 	default:
-		return -EINVAL;
+		return -ENOSYS;
 	}
 }