builddeb: match temporary directory name to the package name

The temporary directory names, debian/hdrtmp (linux-headers package)
vs debian/headertmp (linux-libc-dev package), are confusing.

Matching the directory name to the package name is clearer, IMHO.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/package/builddeb

@@ -47,10 +47,10 @@ create_package() {
 }
 
 version=$KERNELRELEASE
-tmpdir="$objtree/debian/tmp"
-kernel_headers_dir="$objtree/debian/hdrtmp"
-libc_headers_dir="$objtree/debian/headertmp"
-dbg_dir="$objtree/debian/dbgtmp"
+tmpdir="$objtree/debian/linux-image"
+kernel_headers_dir="$objtree/debian/linux-headers"
+libc_headers_dir="$objtree/debian/linux-libc-dev"
+dbg_dir="$objtree/debian/linux-image-dbg"
 packagename=linux-image-$version
 kernel_headers_packagename=linux-headers-$version
 libc_headers_packagename=linux-libc-dev