- remove useless variable "status" from init_main.

http://www.opengroup.org/onlinepubs/009695399/functions/waitpid.html suggests
that we need not specify a status if we don't want, and we don't.
"If wait() or waitpid() return because the status of a child process is available, these functions shall return a value equal to the process ID of the child process. In this case, if the value of the argument stat_loc is not a null pointer, information shall be stored in the location pointed to by stat_loc.  "
   text    data     bss     dec     hex filename
   5391      32       8    5431    1537 init/init.o.06
   5379      32       8    5419    152b init/init.o

init/init.c

@@ -1005,7 +1005,6 @@ int init_main(int argc, char **argv)
 {
 	struct init_action *a;
 	pid_t wpid;
-	int status;
 
 	if (argc > 1 && !strcmp(argv[1], "-q")) {
 		return kill(1,SIGHUP);
@@ -1139,7 +1138,7 @@ int init_main(int argc, char **argv)
 		sleep(1);
 
 		/* Wait for a child process to exit */
-		wpid = wait(&status);
+		wpid = wait(NULL);
 		while (wpid > 0) {
 			/* Find out who died and clean up their corpse */
 			for (a = init_action_list; a; a = a->next) {
@@ -1153,7 +1152,7 @@ int init_main(int argc, char **argv)
 				}
 			}
 			/* see if anyone else is waiting to be reaped */
-			wpid = waitpid (-1, &status, WNOHANG);
+			wpid = waitpid (-1, NULL, WNOHANG);
 		}
 	}
 }