UML: build fix

include/asm-um/arch points to the non-existed include/asm-i386 directory.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@karaya.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/Makefile

@@ -168,7 +168,7 @@ ifneq ($(KBUILD_SRC),)
 	$(Q)mkdir -p $(objtree)/include/asm-um
 	$(Q)ln -fsn $(srctree)/include/asm-$(HEADER_ARCH) include/asm-um/arch
 else
-	$(Q)cd $(TOPDIR)/include/asm-um && ln -fsn ../asm-$(SUBARCH) arch
+	$(Q)cd $(TOPDIR)/include/asm-um && ln -fsn ../asm-$(HEADER_ARCH) arch
 endif
 
 $(objtree)/$(ARCH_DIR)/include: