[CVE-2009-0029] Convert all system calls to return a long

Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/kernel/exit.c b/kernel/exit.c
index c7740fa..fac9b04 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1182,9 +1182,11 @@
  * wait4()-ing process will get the correct exit code - even if this
  * thread is not the thread group leader.
  */
-asmlinkage void sys_exit_group(int error_code)
+asmlinkage long sys_exit_group(int error_code)
 {
 	do_group_exit((error_code & 0xff) << 8);
+	/* NOTREACHED */
+	return 0;
 }
 
 static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)