kbuild: Fix bug in make deb-pkg when using seperate source and output directories

From: Ryan Anderson <ryan@michonline.com>

When running "make O=something deb-pkg", I get a failure that claims I
haven't configured my kernel (I have).  Running it a second time tells
me to run "make mrproper"  (include/linux/version.h got built on the
first run)

Original patch from:
From: Ajay Patel <patela@gmail.com>

With modifications from:
Signed-off-By: Ryan Anderson <ryan@michonline.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/scripts/package/Makefile b/scripts/package/Makefile
index 353b8ea..8afdef9 100644
--- a/scripts/package/Makefile
+++ b/scripts/package/Makefile
@@ -59,7 +59,7 @@
 	$(CONFIG_SHELL) $(MKSPEC) prebuilt > $@
 	
 binrpm-pkg: $(objtree)/binkernel.spec
-	$(MAKE)
+	$(MAKE) KBUILD_SRC=
 	set -e; \
 	$(CONFIG_SHELL) $(srctree)/scripts/mkversion > $(objtree)/.tmp_version
 	set -e; \
@@ -74,7 +74,7 @@
 #
 .PHONY: deb-pkg
 deb-pkg:
-	$(MAKE)
+	$(MAKE) KBUILD_SRC=
 	$(CONFIG_SHELL) $(srctree)/scripts/package/builddeb
 
 clean-dirs += $(objtree)/debian/
diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index 7edd4a0..6edb29f 100644
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -41,7 +41,7 @@
 fi
 
 if grep -q '^CONFIG_MODULES=y' .config ; then
-	INSTALL_MOD_PATH="$tmpdir" make modules_install
+	INSTALL_MOD_PATH="$tmpdir" make KBUILD_SRC= modules_install
 	if [ "$ARCH" == "um" ] ; then
 		mv "$tmpdir/lib/modules/$version"/* "$tmpdir/usr/lib/uml/modules/$version/"
 		rmdir "$tmpdir/lib/modules/$version"