[PATCH] 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?

arch/i386/kernel/sys_i386.c

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