[ATM]: add+use poison defines

ATM: add and use POISON define values.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/poison.h b/include/linux/poison.h
index 05d7d0f..3e628f9 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -44,6 +44,7 @@
 
 /********** drivers/atm/ **********/
 #define ATM_POISON_FREE		0x12
+#define ATM_POISON		0xdeadbeef
 
 /********** net/ **********/
 #define NEIGHBOR_DEAD		0xdeadbeef