Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "2 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  zsmalloc: fix zs_can_compact() integer overflow
  Revert "proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan""

fs/proc/base.c

@@ -434,7 +434,7 @@ static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
 			&& !lookup_symbol_name(wchan, symname))
 		seq_printf(m, "%s", symname);
 	else
-		seq_puts(m, "0\n");
+		seq_putc(m, '0');
 
 	return 0;
 }

mm/zsmalloc.c

@@ -1735,10 +1735,13 @@ static struct page *isolate_source_page(struct size_class *class)
 static unsigned long zs_can_compact(struct size_class *class)
 {
 	unsigned long obj_wasted;
+	unsigned long obj_allocated = zs_stat_get(class, OBJ_ALLOCATED);
+	unsigned long obj_used = zs_stat_get(class, OBJ_USED);
 
-	obj_wasted = zs_stat_get(class, OBJ_ALLOCATED) -
-		zs_stat_get(class, OBJ_USED);
+	if (obj_allocated <= obj_used)
+		return 0;
 
+	obj_wasted = obj_allocated - obj_used;
 	obj_wasted /= get_maxobj_per_zspage(class->size,
 			class->pages_per_zspage);