powerpc/eeh: remove unused macro IS_BRIDGE

Currently, the macro IS_BRIDGE is not used any where.
This patch just removes it.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 04b5d94..23e0aa7 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -144,8 +144,6 @@
 
 static struct eeh_stats eeh_stats;
 
-#define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE)
-
 static int __init eeh_setup(char *str)
 {
 	if (!strcmp(str, "off"))