There is no need to record stack trace and immediately print it.  Just
use dump_stack() to print the current stack.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
 static int __check_holder(struct block_lock *lock)
 {
        unsigned i;
-#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
-       static struct stack_trace t;
-       static stack_entries entries;
-#endif
 
        for (i = 0; i < MAX_HOLDERS; i++) {
                if (lock->holders[i] == current) {
                        print_stack_trace(lock->traces + i, 4);
 
                        DMERR("subsequent acquisition attempted here:");
-                       t.nr_entries = 0;
-                       t.max_entries = MAX_STACK;
-                       t.entries = entries;
-                       t.skip = 3;
-                       save_stack_trace(&t);
-                       print_stack_trace(&t, 4);
+                       dump_stack();
 #endif
                        return -EINVAL;
                }