[S390] Add oops_enter()/oops_exit() calls to die().

This is mainly to switch off all potentially debugging stuff that
won't report anything useful after an oops happened.
Besided that setting pause_on_oops will work too, but doesn't make
too much sense on s390.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/traps.c

@@ -253,6 +253,7 @@ void die(const char * str, struct pt_regs * regs, long err)
 {
 	static int die_counter;
 
+	oops_enter();
 	debug_stop_all();
 	console_verbose();
 	spin_lock_irq(&die_lock);
@@ -266,6 +267,7 @@ void die(const char * str, struct pt_regs * regs, long err)
 		panic("Fatal exception in interrupt");
 	if (panic_on_oops)
 		panic("Fatal exception: panic_on_oops");
+	oops_exit();
 	do_exit(SIGSEGV);
 }