[PKT_SCHED]: Fix range in PSCHED_TDIFF_SAFE to 0..bound

Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit d5f65671be760f33c1c7667f793ed75ad6e6a710
tree 4af3018396f125b0c2601882d924e63a0d74bef4
parent 980207c270e72e2cc6ae7b0de6ea6cd38a726e5b
author Patrick McHardy <kaber@trash.net> 1114776755 +0200
committer Patrick McHardy <kaber@trash.net> 1114776755 +0200

Index: include/net/pkt_sched.h
===================================================================
--- e38e7620d369bfa898a2e3f6aaf2f04c8826f38e/include/net/pkt_sched.h  (mode:100644 sha1:7352e455053cc857e70f0cb1e008eb7adabbe011)
+++ 4af3018396f125b0c2601882d924e63a0d74bef4/include/net/pkt_sched.h  (mode:100644 sha1:fcb05a387dbee560d6a0f20b6e8c3c4f1b2d93f1)
@@ -157,7 +157,8 @@
 	   case 1: \
 		   __delta += 1000000; \
 	   case 0: \
-		   __delta = abs(__delta); \
+ 		   if (__delta > bound || __delta < 0) \
+ 			__delta = bound; \
 	   } \
 	   __delta; \
 })