ipc/compat.c: remove sc_semopm macro

This macro appears to have been introduced back in the 2.5 era for
semtimedop32 backward compatibility on ia32:

  https://lkml.org/lkml/2003/4/28/78

Nowadays, this syscall in compat just defaults back to the code found in
sem.c, so it is no longer used and can thus be removed:

long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
		unsigned nsops, const struct compat_timespec __user *timeout)
{
	struct timespec __user *ts64;
	if (compat_convert_timespec(&ts64, timeout))
		return -EFAULT;
	return sys_semtimedop(semid, tsems, nsops, ts64);
}

Furthermore, there are no users in compat.c.  After this change, kernel
builds just fine with both CONFIG_SYSVIPC_COMPAT and CONFIG_SYSVIPC.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/compat.c

@@ -113,9 +113,6 @@ struct compat_shm_info {
 	compat_ulong_t swap_attempts, swap_successes;
 };
 
-extern int sem_ctls[];
-#define sc_semopm	(sem_ctls[2])
-
 static inline int compat_ipc_parse_version(int *cmd)
 {
 #ifdef	CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION