s390/stacktrace: Remove the pointless ULONG_MAX marker

Terminating the last trace entry with ULONG_MAX is a completely pointless
exercise and none of the consumers can rely on it because it's
inconsistently implemented across architectures. In fact quite some of the
callers remove the entry and adjust stack_trace.nr_entries afterwards.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Link: https://lkml.kernel.org/r/20190410103644.396788431@linutronix.de

arch/s390/kernel/stacktrace.c

@@ -45,8 +45,6 @@ void save_stack_trace(struct stack_trace *trace)
 
 	sp = current_stack_pointer();
 	dump_trace(save_address, trace, NULL, sp);
-	if (trace->nr_entries < trace->max_entries)
-		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
 EXPORT_SYMBOL_GPL(save_stack_trace);
 
@@ -58,8 +56,6 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	if (tsk == current)
 		sp = current_stack_pointer();
 	dump_trace(save_address_nosched, trace, tsk, sp);
-	if (trace->nr_entries < trace->max_entries)
-		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
 
@@ -69,7 +65,5 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
 
 	sp = kernel_stack_pointer(regs);
 	dump_trace(save_address, trace, NULL, sp);
-	if (trace->nr_entries < trace->max_entries)
-		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_regs);