Reflect latest interface changes; return 0 on success and -1 on error.

sysdeps/linux/sem_limits.c

@@ -54,6 +54,8 @@ int
 glibtop_init_sem_limits_s (glibtop *server)
 {
 	server->sysdeps.sem_limits = _glibtop_sysdeps_sem_limits;
+
+	return 0;
 }
 
 /* Provides information about sysv ipc limits. */
@@ -83,4 +85,6 @@ glibtop_get_sem_limits_s (glibtop *server, glibtop_sem_limits *buf)
 	buf->semusz = seminfo.semusz;
 	buf->semvmx = seminfo.semvmx;
 	buf->semaem = seminfo.semaem;
+
+	return 0;
 }