[PATCH] uml: Fix conflict between libc and ipv6

gcc is now complaining during link on some hosts - fix it as for other things.
Reported by Antoine Martin <antoine@nagafix.co.uk>.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/Makefile

@@ -53,9 +53,13 @@ SYS_DIR		:= $(ARCH_DIR)/include/sysdep-$(SUBARCH)
 
 # -Dvmap=kernel_vmap affects everything, and prevents anything from
 # referencing the libpcap.o symbol so named.
+#
+# Same things for in6addr_loopback - found in libc.
 
 CFLAGS += $(CFLAGS-y) -D__arch_um__ -DSUBARCH=\"$(SUBARCH)\" \
-	$(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap
+	$(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap \
+	-Din6addr_loopback=kernel_in6addr_loopback
+
 AFLAGS += $(ARCH_INCLUDE)
 
 USER_CFLAGS := $(patsubst -I%,,$(CFLAGS))