um: merge arch/um/sys-{i386,x86_64}/shared

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/Makefile b/arch/um/Makefile
index c121870..184494d 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -25,9 +25,8 @@
 
 SHARED_HEADERS	:= $(ARCH_DIR)/include/shared
 ARCH_INCLUDE	:= -I$(srctree)/$(SHARED_HEADERS)
-ARCH_INCLUDE	+= -I$(srctree)/$(ARCH_DIR)/sys-$(SUBARCH)/shared
+ARCH_INCLUDE	+= -I$(srctree)/$(ARCH_DIR)/sys-$(HEADER_ARCH)/shared
 KBUILD_CPPFLAGS += -I$(srctree)/$(ARCH_DIR)/sys-$(HEADER_ARCH)
-KBUILD_CPPFLAGS += -I$(srctree)/$(ARCH_DIR)/sys-$(SUBARCH)
 
 # -Dvmap=kernel_vmap prevents anything from referencing the libpcap.o symbol so
 # named - it's a common symbol in libpcap, so we get a binary which crashes.