kbuild: deb-pkg: do not take KERNELRELEASE from the source version

KERNELRELEASE does not need to match the package version in changelog.
Rather, it conventially matches what is called 'ABINAME', which is a
part of the binary package names.

Both are the same by default, but the former might be overridden by
KDEB_PKGVERSION. In this case, the resulting package would not boot
because /lib/modules/$(uname -r) does not point the module directory.

Partially revert 3ab18a6 ("kbuild: deb-pkg: improve the usability
of source package").

Reported-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Fixes: 3ab18a6 ("kbuild: deb-pkg: improve the usability of source package")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/package/deb-build-option

@@ -8,9 +8,8 @@ if [ -z "${CROSS_COMPILE}${cross_compiling}" -a "${DEB_HOST_ARCH}" != "${DEB_BUI
 fi
 
 version=$(dpkg-parsechangelog -S Version)
-version_upstream="${version%-*}"
-debian_revision="${version#${version_upstream}}"
-debian_revision="${debian_revision#*-}"
+debian_revision="${version##*-}"
 
-echo KERNELRELEASE=${version_upstream}
-echo KBUILD_BUILD_VERSION=${debian_revision}
+if [ "${version}" != "${debian_revision}" ]; then
+	echo KBUILD_BUILD_VERSION=${debian_revision}
+fi

scripts/package/mkdebian

@@ -243,6 +243,7 @@ srctree ?= .
 build-indep:
 build-arch:
 	\$(MAKE) -f \$(srctree)/Makefile ARCH=${ARCH} \
+	KERNELRELEASE=\$(KERNELRELEASE) \
 	\$(shell \$(srctree)/scripts/package/deb-build-option) \
 	olddefconfig all