linux: Fix tst-syscall-restart.c on old gcc (BZ 32283)

To avoid a parameter name omitted error.

sysdeps/unix/sysv/linux/tst-syscall-restart.c

@@ -57,7 +57,7 @@ check_pid (pid_t pid)
 }
 
 static void *
-tf (void *)
+tf (void *closure)
 {
   pause ();
   return NULL;