installplatform: drop unsused variables from the script

installplatform

@@ -88,12 +88,9 @@ case "$arch" in
     SUBSTS='y___'
     ;;
 esac
-base_arch=`echo $arch | sed -e 's_i?86_i386_;s_sparc.*_sparc_;s_alpha.*_alpha_;s_\(powerpc\|ppc\).*_ppc_;s,amd64,x86_64,'`
 
 for SUBST in $SUBSTS ; do
   ARCH=`echo $arch | sed -e $SUBST`
-  TARGET_PLATFORM=`echo $target_platform | sed -e $SUBST`
-  TARGET=`echo $target | sed -e $SUBST`
   LIBSUFF=
   POINTER_SIZE=32