[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>

kernel/timer.c

@@ -1129,7 +1129,7 @@ void do_timer(unsigned long ticks)
  * For backwards compatibility?  This can be done in libc so Alpha
  * and all newer ports shouldn't need it.
  */
-asmlinkage unsigned long sys_alarm(unsigned int seconds)
+asmlinkage long sys_alarm(unsigned int seconds)
 {
 	return alarm_setitimer(seconds);
 }