Miscellaneous code cleanup.

servers/ipc/sem.c

@@ -287,7 +287,6 @@ PUBLIC int do_semctl(message *m)
 	unsigned short *buf;
 	struct semid_ds *ds, tmp_ds;
 	struct sem_struct *sem;
-	struct semaphore *semaphore;
 
 	id = m->SEMCTL_ID;
 	num = m->SEMCTL_NUM;

servers/ipc/shm.c

@@ -184,10 +184,9 @@ PUBLIC void update_refcount_and_destroy(void)
  *===========================================================================*/
 PUBLIC int do_shmdt(message *m)
 {
-	struct shm_struct *shm;
 	vir_bytes addr;
 	phys_bytes paddr;
-	int n, i;
+	int i;
 
 	addr = m->SHMDT_ADDR;