sctp: fix checkpatch errors with indent

fix checkpatch errors below:
ERROR: switch and case should be at the same inden
ERROR: code indent should use tabs where possible

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index a4f1743..a987d54 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -69,7 +69,7 @@
 	if ((event_subtype._type > (_max))) {				\
 		pr_warn("table %p possible attack: event %d exceeds max %d\n", \
 			_table, event_subtype._type, _max);		\
-	        rtn = &bug;						\
+		rtn = &bug;						\
 	} else								\
 		rtn = &_table[event_subtype._type][(int)state];		\
 									\