[PATCH] kbuild: build TAGS problem with O=

  make O=/dir TAGS

  fails with:

    MAKE   TAGS
  find: security/selinux/include: No such file or directory
  find: include: No such file or directory
  find: include/asm-i386: No such file or directory
  find: include/asm-generic: No such file or directory

  The problem is in this line:
  ifeq ($(KBUILD_OUTPUT),)

KBUILD_OUTPUT is not defined (ever) after make reruns itself.  This line is
used in the TAGS, tags, and cscope makes.

Signed-off-by: George Anzinger <george@mvista.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Makefile b/Makefile
index 278d509..2717223 100644
--- a/Makefile
+++ b/Makefile
@@ -1149,7 +1149,7 @@
 #(which is the most common case IMHO) to avoid unneeded clutter in the big tags file.
 #Adding $(srctree) adds about 20M on i386 to the size of the output file!
 
-ifeq ($(KBUILD_OUTPUT),)
+ifeq ($(src),$(obj))
 __srctree =
 else
 __srctree = $(srctree)/