kbuild: deb-pkg: clean up package name variables

Hard-code the names of linux-headers and debug packages in the
control file.

The kernel package is different for ARCH=um. Change the code
for better readability.

Signed-off-by: Masahiro Yamada <[e-mail]>

scripts/package/mkdebian

···
 	packageversion=$version-$revision
 fi
 sourcename=$KDEB_SOURCENAME
-packagename=linux-image-$version
-kernel_headers_packagename=linux-headers-$version
-dbg_packagename=$packagename-dbg
-debarch=
-set_debarch
 
 if [ "$ARCH" = "um" ] ; then
-	packagename=user-mode-linux-$version
+	packagename=user-mode-linux
+else
+	packagename=linux-image
 fi
+
+debarch=
+set_debarch
 
 email=${DEBEMAIL-$EMAIL}
 
···
 Build-Depends: bc, rsync, kmod, cpio, bison, flex | flex:native $extra_build_depends
 Homepage: https://www.kernel.org/
 
-Package: $packagename
+Package: $packagename-$version
 Architecture: $debarch
 Description: Linux kernel, version $version
  This package contains the Linux kernel, modules and corresponding other
···
 if is_enabled CONFIG_MODULES; then
 cat <<EOF >> debian/control
 
-Package: $kernel_headers_packagename
+Package: linux-headers-$version
 Architecture: $debarch
 Description: Linux kernel headers for $version on $debarch
  This package provides kernel header files for $version on $debarch
···
 if is_enabled CONFIG_DEBUG_INFO; then
 cat <<EOF >> debian/control
 
-Package: $dbg_packagename
+Package: linux-image-$version-dbg
 Section: debug
 Architecture: $debarch
 Description: Linux kernel debugging symbols for $version