net_sched: add missing paddattr description

"make htmldocs" complains otherwise:

.//net/core/gen_stats.c:65: warning: No description found for parameter 'padattr'
.//net/core/gen_stats.c:101: warning: No description found for parameter 'padattr'

Fixes: 9854518ea04d ("sched: align nlattr properly when needed")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/gen_stats.c

@@ -47,6 +47,7 @@ nla_put_failure:
  * @xstats_type: TLV type for backward compatibility xstats TLV
  * @lock: statistics lock
  * @d: dumping handle
+ * @padattr: padding attribute
  *
  * Initializes the dumping handle, grabs the statistic lock and appends
  * an empty TLV header to the socket buffer for use a container for all
@@ -87,6 +88,7 @@ EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  * @type: TLV type for top level statistic TLV
  * @lock: statistics lock
  * @d: dumping handle
+ * @padattr: padding attribute
  *
  * Initializes the dumping handle, grabs the statistic lock and appends
  * an empty TLV header to the socket buffer for use a container for all