lockdep: Remove the ULONG_MAX stack trace hackery

No architecture terminates the stack trace with ULONG_MAX anymore. Remove
the cruft.
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: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190410103644.485737321@linutronix.de

kernel/locking/lockdep.c

@@ -444,17 +444,6 @@ static int save_trace(struct stack_trace *trace)
 
 	save_stack_trace(trace);
 
-	/*
-	 * Some daft arches put -1 at the end to indicate its a full trace.
-	 *
-	 * <rant> this is buggy anyway, since it takes a whole extra entry so a
-	 * complete trace that maxes out the entries provided will be reported
-	 * as incomplete, friggin useless </rant>
-	 */
-	if (trace->nr_entries != 0 &&
-	    trace->entries[trace->nr_entries-1] == ULONG_MAX)
-		trace->nr_entries--;
-
 	trace->max_entries = trace->nr_entries;
 
 	nr_stack_trace_entries += trace->nr_entries;